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vol.48-1(2010/5/31)
| Environmental indoor allergens |
| In most areas of the world, house dust mites, animals and funguses are the most important sources of allergens in the indoor environment. Especially mite allergens are strongly associated with asthma, perennial rhinitis, and atopic dermatitis. There have been many studies of house-dust mite allergen control and avoidance. To evaluate the extent of exposure to airborne mite allergens, we measured major mite allergens in indoor environments with immunoassay using allergen-specific antibodies. The levels of mite allergens trapped by the sampler were measured with a highly sensitive immunoassay. We found heavy exposure to mite allergens from bedding during sleeping. Bedding is likely one of the major reservoirs of mite allergens. When the used bedding was replaced with new allergen-free bedding, we detected a decrease in the airborne allergen levels. |
| Mite allergen in an indoor environment |
| A one-third Japanese people has some allergic symptoms, and there is the number in an increase tendency year by year now. As for the cause that allergy population increased like this, the mites increased rapidly due to the change of our life style and the change in the indoor environment is deeply concerned with a rapid increase of the allergic patient. In this report, it gave the outline about mite allergen in house dust. And also, the kind of mite, mechanism of pathogenesis of mite allergen, measurement methods of mite allergen, mite allergen control method which referred the latest knowledge are introduced. Our life diversifies more and more, and opportunities to contact with allergen such as a dog, cat, fungi and cockroach in the room will increase as well as mite allergen in future. From a view point of preventive medicine, it is important to decrease these allergen. |
| Fungal allergen in indoor environments |
| Fungi related to allergies are commonly found in indoor environments. The predominant fungi such as Cladosporium, Penicillium, Aspergillus, Alternaria, and Wallemia live mainly in indoor air, dust, clothes and contaminated dwelling materials. Fungi in dust and air are especially important harmful allergens for human health. Air borne fungi in indoor are inclined to increase on June to July and August to October in Japan. Fungi are the causative agents of allergy and retain with a serious human health problem because the fungal cells scatter from the air or dust. The biological activities on the spore germination, enzyme activities, viable or nonviable cells and fungal fragments also have health implications from the viewpoint of fungal allergens. In this paper, ecological and mycological investigation of indoor environments is discussed in point of fungal allergens. |
| Pet allergens in indoor environment |
| Cats and dogs are important sources of indoor allergens. Fel d 1 was demonstrated to be a major allergen from cats. Can f 1 was purified as a major allergen in dog hair and dander extracts. We tried to assess the extent of natural exposure to cat and dog allergens in the houses in which these animals are kept as pets. We measured the absolute concentrations of airborne Fel d 1 and Can f 1 allergens in the living rooms where the inhabitants had been living as usual and compared the levels of airborne cat and dog allergens with those of airborne mite allergens. The levels of airborne Fel d 1 and Can f 1 in houses with cats and dogs were more than 100 times higher than levels of airborne mite allergens. These results suggested that the airborne cat and dogs allergens might be important sources of allergens for persons who live in a house with those animals, because the absolute allergen levels in both the air and dust are significantly higher than those of mite. |
| JIS B 9917-8 : 2010 |
| JIS B 9920 applied the classification of airborne particles cleanliness in cleanrooms and associated controlled environments. The JIS B 9917-8 covers the classification of airborne molecular contamination (AMC) in cleanrooms and associated controlled environments in terms of airborne concentrations of specific chemical species (individual, group or category) and provides a protocol to include test methods, analysis and time weighted factors within the specification for classification. This standard considers only concentrations of AMC between 106 and 10-3 ng/m3 under cleanroom operational conditions. This standard does not give a classification of surface molecular contamination. |
| Structure and Characteristics of Deodorizing Filters |
| Recently, public consciousness about the environmental problems has become more intense than before, especially, the number of civilian's complaints regarding smell is increasing. On the other hand, personal estimation on smell may differ depending upon the situation and the sense of smell of each observer, for example, even intense fragrance may sometimes be estimated as "smell". Therefore, it is strongly required to eliminate materials which emit odor as much as possible. This paper was made to facilitate the studies on the fundamental technology against smell and also the selection of types of air filters, deodorants, etc. most suitable for each application. |
vol.48-2(2010/7/31)
| Environmental evaluation in vehicle cabin (review article) |
| The artificial environment that is the space where man lives is important. The thermal environment and the air quality environment in the car room that is one of the artificial environments exert a big influence directly on man's health and amenity. Especially, the evaluation of the thermal environment is indispensable to coexist about the amenity and energy conservation. This chapter introduces the outline of the thermal environment and the air quality environment as an evaluation in the indoor condition of the vehicle, and it introduces "Thermal environment evaluation (ISO14505 etc.) in the vehicle cabin", "Air quality environment evaluation (VOC etc.) in the vehicle cabin", "Latest trend of the air-conditioning technology in the vehicle", and "Latest trend of the air-conditioning technology in the railway vehicle" in each chapter after this. |
| Evaluation of thermal environment in vehicles (ISO14505) |
| A climate control system of the vehicle is basically designed to meet the very hot or very cold environment from the safety point of view. Otherwise, the comfortableness in the compartment also has been paid attention from the commercial point of view. At the same time, as enhancement of the conscious of the global warming protection, the development of the high performance air-conditioning system is required. Accordingly, the quantitative evaluation of the thermal environment of the vehicle compartment is inevitable for the reasonable development and design. Recently, ISO has constituted new standard of ISO-14505 to determine the evaluation method of the compartments for the various kinds of vehicles. Meanwhile, relating to the tendency of the high efficiency development, the investigation of the predictive evaluation method has been conducted. Then, this report introduces new trend of the standardization of the evaluation method of the thermal environment of vehicles. |
| Evaluation methods for cabin air quality |
| For the improvement of the air quality of indoors, it is necessary to detremine the kinds and the concentration of the chemical substances that emit from building products and production parts. As for the VOCs (Volatile Organic Compounds) concentration that emitted from this vehicle cabin, the VOCs concentration is greatly different depending on the temperature when measuring it. Then, the thing that Arrhenius rule consists from the real car measurement data with different measurement temperature between the toluene concentrations that were a typical substances of a measurement temperature and Cabin VOC car was confirmed, and it proposed the concentration conversion formula this research. Moreover, the substances that had emitted from parts was clarified from the measurement of VOCs and SVOCs of part single goods with a generation gas concentrate device (MSTD). Furthermore, it has been understood to be able to decrease VOCs of cabin concentration of the car promptly and efficiently by doing the decrease measures of VOCs selecting parts with a lot of VOCs volatilization volumes. VOCs is mentioned as big environmental problems that should work in each industrial world. When the VOCs generated from the interior material etc. of the new car is measured, the elapsed time from the day of the vehicle manufacturing and the condition of the cabin temperature of the car greatly take part in the concentration of the VOCs. |
| The latest technologies of air-conditioning and heating in passenger and commercial vehicles |
| HVAC systems of passenger and commercial vehicles have some features in their performance and functions compared with those of residential buildings. Some characteristics of those systems are introduced in this paper. Futher more, latest technologies of air-conditioning and heating in passenger and commercial vehicles, such as the seat ventilation system, the matrix infrared sensor system, the pollen removal mode, the oxygen generator, the ejector system, the internal heat exchanger system, the hot gas heater, the main engine direct driven bus air-conditioning system, and the package air-conditioning system applying commercial power source are introduced. |
| Recent technology status and trend on air conditioning systems for train |
| The air conditioning system for railroad vehicles has a history of over 70 years' service, ever since it first was applied for special express trains as a means to improve passenger comfort by conditioning the saloon temperature and humidity. The train air conditioning system now such an important role that no existing railroad vehicles does without one including special expresses, commuters, Sinkansen, new traffic, a street car, and a monorail. The air conditioning system for railroad vehicles faces quite different circumstances from that of residential air conditioning system because of its unique setting that allows load weight impacts, door opening and closing, changing air conditions, installation constraints and possible vibration and voltage variation caused by driving. In addition to that, the structure of trains and the state of their functions also ask for their air conditioning systems to be individually custom designed if we seek the best. I describe to introduce the installation methods and some of the latest models of commuters and Sinkansen air conditioning systems as examples, with related historical backgrounds. |
| The risk assessment of advanced technologies for aseptic production and the adaptation of new microbial monitoring technologies in near future |
| The advanced technologies for the aseptic manufacturing has been significantly improved the aseptic assurance level in teams of the environmental microbial contamination risk reduction. The risk levels of Isolator, RABS and the conventional Grade A/B were evaluated by numerical methods. The clear results have been shown the superiority of the advanced technologies like Isolator and RABS. In those advanced facilities, no countable incident ratio of the microbial monitoring is available since the monitoring results are usually all negative. This result implicates the necessity of the next technology revolution in microbial environmental monitoring methods. Three newly emerging mocrobial air monitoring technologies in Japan, like Rapid Microbial Monitoring (RMM), are introduced in this article. On the other hand, a practical evaluation method for identifying the microbial air contamination risks in a conventional Grade A/B by utilizing CFD simulation and actual three dimensional air vectors measuring is also introduced. |
| Overview of needs for clean technology and analytical technology in semiconductor process |
| Demanded values for clean technology in the semiconductor processes and necessary analytical technology are described based on the international technology roadmap for semiconductors (ITRS). Today's analytical technology in the point of trace analysis generally agrees with the demand of ITRS. The direct total reflection X-ray fluorescence (TXRF) measurement and the technique of combining the chemical separation method for the metals from the surface with inductively coupled plasma mass spectrometry or TXRF are used for the metal contamination. It is a main current that thermal desorption gas chromatograph mass spectrometry is used for the surface ortanic molecules. |
vol.48-3(2010/9/30)
| Outline of JACA's energy saving WG activity for a semiconductor factory |
| This paper introduces the activities that the Clean Room Energy Saving Committee of JACA has done so far and is planning to do in the future. At the same time, it also describes the outline of the cooperative activities with Semiconductor Equipment Association of Japan and Japan Electronics and Information Technology Industries Association, which are aimed at saving energy in manufacturing equipments and semiconductor facility. |
| The Overview of the Simplified Calculating System of Energy Consumed in Factory |
| The Clean Room Energy Saving Committee of Japan Air Cleaning Association released the revised version (Version 2.1) of "The Simplified Calculating System of Energy Consumed in Factory" in 2008. This program is a tool to conduct an energy simulation in a semiconductor factory in a simple way. This paper describes the overview of functions, architecture, applications, and usage of the program. |
| Explanation on the Simplified Calculating System of Energy Consumed in Factory |
| "The Simplified Calculating System of Energy Consumed in Factory (Revised Version 2.1)" is a program which simply calculates annual energy consumption in a factory, and was released from Japan Air Cleaning Association in 2008. According to the processing flow of the program, this article explains the overview of the program architecture, conditions of calculation input, and calculation process. |
| Examples of Comparative Calculations at a Model Factory Utilizing the "Simplified Calculating System of Energy Consumed in Factory" |
| Using "The Simplified Calculating System of Energy Consumed in Factory", we conducted comparative calculations at a model factory and considered about introduction of energy-saving methods. In addition to re-examination of several numerical values, a function to consider about energy saving was added to the system. As a result, the system now allows more detailed comparisons. |
| Building cooling plant system with high efficient energy savings and the performance deterioration in the way of low-carbon society |
| There are three important elements in building system energy savings and low carbon. The first element is that the low carbon and energy consumption rate of building system is less than the existing system. The second one is to raise the system reliability. The system works as expected by how the risk of faults can be avoided. The third one is that the system performance does not deteriorate as much as possible. For example, suppose that the investment effect is judged based on the current value of total payments over 15 years. If the discount rate is 5%, the estimated total effect value when performance deterioration is considered is about 1.4 times higher than when it is not considered. Even if the initial investment is considered, the estimated total amount of the former case will be 1.2 times or more of the latter case. This clearly illustrates the importance of minimizing performance deterioration. |
| Mitigation of global warming in semiconductor manufacturing |
| Mitigation of global warming has been urgent issue recently. Life cycle energy consumption of a semiconductor device is not so large, however usage of the devices in huge applications possibly come to massive amount of energy consumption. Energy consumption in life cycle consists of energy in manufacturing and energy in usage. Suppression of the energy in manufacturing is one of big issue to mitigate global warming. Semiconductor manufacturing needs the clean room that provides super clean ambient, precisely-controlled room temperature, humidity and contamination free for microfabrication. And also it needs many kinds of production equipments over thousand. Hence the clean room requires huge energy, chemicals, water and gases. The energy consumption of a clean room comes near the energy use of half a million people city, therefore energy saving and green house gas reduction are very important. Measure of energy saving is reduction of each equipment energy consumption basically. In addition that, dynamic power control depended on actual needs are very important for further improvement, for example, intermittent operation of a dry pump and sleep mode during standby status of the equipment. The other important measures are information exchange in detail among device maker, production equipment maker and facility maker, and visualization of energy to understand effectiveness. |
| Energy-saving technology in semiconductor manufacturing equipment |
| Saving energy in semiconductor manufacturing equipment will bring about the great merit for the global warming. SEMI S23 is a useful guideline to reduce total energy consumption in semiconductor manufacturing equipment. Based on SEMI S23, we implemented life cycle assessment on 300-mm tools. As the result of energy-conservation calculation on LP-CVD tool, the annual CO2 emission is going to be reduced by 40 tons of emission. |
| Indoor environment and workplace productivity |
| The idea of workplace productivity in office was attracted attention after the office automation system was applied in the office building in 1980's. Now the term "workplace productivity" has been seen in various architectural literatures. Recently the results of the studies in these fields have been put together in many books and have begun to try to apply these concepts to architectural planning. As physical effect factors for workplace productivity, there are light environment, sound environment, thermal environment, indoor air environment, interior design, and introduction situation of ICT (Information and Communication Technology). There is much research on the relations of workplace productivity with indoor air quality, which shows that the volume of fresh air or perceived air quality influences workplace-productivity. Many subjective and objective measuring methods of the workplace productivity have been proposed until now, in this paper the latest subjective measuring method "SAP" is introduced. |
| Particle Measurement in Cleanrooms for Semiconductor Manufacturing |
| The processing technology of semiconductors is advance in day by day and high integrated semiconductors are manufactured. The manufacturing equipment, clean environment, chemicals and processing gases support this processing technology. The particle counters are widely use for evaluation of environment and cleanliness of chemicals for semiconductor manufacturing. The measurement and the control of the particle are necessary for improving and maintaining the yield of semiconductor production. The principle and characteristic of particle counters will be explained, additionally notice points for particle measurement will be explained. |
vol.48-4(2010/11/30)
| Energy Conservation Control System for the Secondary conveying Pumps of Air-Conditioning Facilities |
| This paper introduces an energy conservation technology for the secondary conveying pumps of air conditioning facilities. This technology "Predictive pipe friction control," when compared with conventional technologies to control the pressure at a fixed value using an inverter, enables further energy conservation by reducing motor frequency down to the pressure corresponding to a required flow rate. This paper first explains the theory and the feature of this technology that can attain good energy conservation effect. It also picks up a case to have challenged energy conservation countermeasures at a real semiconductor factory as well as this system that was adopted as one of the energy-saving countermeasures, for the purpose of introducing the energy conservation countermeasure case in an air conditioning load pattern different from those of offices or commercial facilities. |
| Energy saving of humidity adjustment in a clean room |
| Two energy saving techniques concerning the humidity adjustment in a clean room are introduced. One is a control system that automatically lowers the reheat temperature. The overcooling and the reheat operation are done for the humidity conditioning. The energy consumption is large because cooling and heating are done at the same time. The control system that adjusted a set value of the reheat temperature according to the heat load situation of each area of a clean room was developed. Next, the water spray method was used to humidify in a clean room. Water was sprayed into the chamber of the return air in a clean room. The amount of humidifying in the makeup air processor decreases, and the energy cunsumption related to humidifying has been reduced greatly. |
| Optimal plan applied to computational fluid dynamics |
| In the HVAC sector we propose various energy-saving methods, such as to improve the efficiency of equipment unit or system, the use of natural energy. In order to provide better air-conditioning, we must consider about comfortable indoor environment and production environments that meet the specification conditions, as well as energy-saving effect. However, to deliver the energy-saving effect, productivity and a comfort is very difficult. We have developed 'energy-saving suggestion tool by CFD'. The tool can evaluate HVAC energy-saving effect, comfort and productivity, and suggest the solution. We apply the tool to an energy-saving suggestion and designing HVAC system. |
| None cross-contaminated heat recovery system |
| Without a heat recovery system, a significant amount of energy is wasted by the exhaust air in an air-conditioning system that requires a large percentage of outdoor air. To eliminate the risk of cross-contamination in facilities of semiconductor manufacturing, pharmaceutical manufacturing and laboratory animal, run-around coil heat recovery systems are utilized rather than high efficiency heat wheel type heat exchangers. We developed a run-around wet coil system with water showering unit installed on top of the finned tube coil. The sprayed or dripped water makes the finned tube surface wet to improve heat transfer efficiency, and makes the evaporative latent heat available. As a result, a big improvement of heat recovery efficiency is achieved. |
| New technologies for reducing negative environmental impact in semiconductor factory |
| Clean rooms consume a great deal of energy for air conditioning and semiconductor factories contain clean rooms in many cases. The introduction of technologies that can reduce air conditioning energy consumption is very important. In this paper, we introduce the following technologies: 1)Pump flow volume control system for refrigeration equipment 2)Hybrid room pressure control system 3)Requires no ceiling duct work They are developed for energy saving and reducing negative environmental impact. Semicondoctor factories can easily and sppedily install these convenient technologies. |
| Studying energy saving technologies of clean room systems from the point of view of that's own merits and demerits |
| The clean room energy consumption for the semiconductor industry is very large compared with common HVAC. So, various countermeasures are installed for energy saving. And there are many merits on each method but that's merits are too much emphasized, demerits are left behind to solve. The nature is not consisted of advantages only but also disadvantages on the balance. These technologies of well used in clean room shall be checked whether demerits are in or not, and when demerits are solved, these become more comfortable technologies for nature. |
| Energy conservation system used the waste heat of low temperature and the media for vaporizing type humidifier |
| In clean rooms for manufacturing semicondoctor and FPD and so on, it is necessary to control the temperature and humidity precisely. And also, a lot of energy is consumed for air conditioning in those rooms because they use a large volume of outdoor air. Therefore, we have developed the energy cunservation system used the waste heat of low temperature and the media for the vaporizing type humidifier. This system can control the humidity proportionally even by the vaporizing type humidify however it was difficult until now. In addition, this system can use the low temperature cooling water of about 30℃ discharged from the ciller and manufacturing device however it was not useful until now. By using two techniques mentioned above, we realized to reduce significantly the amount of fossil fuel for the steam humidify and CO2 emission. By way of example, we tried to calculate the reduction rate of energy consumption, CO2 emission and running cost for the conventional air conditioner at the factory (24℃, 50%) in Nagano prefecture. As a result, energy consumption was reduced up to 57%, CO2 emission was 53% and running cost was 53%. Moreover, the adaptation cost from the conventional air conditioner to this system can be amortized in 0.7years. |
| Energy saving chilled water system using free-cooling for cleanroom |
| This paper describes the heat source system with a newly developed automatic operation technology for free-cooling which makes up cold water by using cooling tower. The system also adopted high efficient inverter turbo refrigerators and work condition optimization technologies. These technologies enabled the COP of this system as high as 10 and 50% reduction of power consumption (in-house comparison). |
| JIS for Particle Counters |
| The JIS B 9921 for airborne particle counter and JIS B 9925 for liquid borne particle counter are revised because of the ISO 21501-4 and -2 were published in 2007. The new JIS B 9916 for light extinction liquid borne particle counter was published according to the ISO 21501-3. The differences between new JIS and old JIS are explained in this paper. |
| Monitoring for Molecular Contaminants in Semiconductor Production Lines |
| Airborne molecular contaminants (AMC) such as acid, ammonia, amine, and organic compounds in advanced semiconductor manufacturing cleanrooms and equipments cause integrated circuits yield loss. The AMC haze the surfaces of reticle and mirror. On lithography process, ammonia and amines result in the T-TOP phenomenon by hydrogen drawing reaction to the chemical amplification resist. It is thought that acidic gaseous contaminants corrode Cu wirings directly. Therefore, it is important to control the AMC in the cleanrooms and equipments. In this paper, I report to describe analytical methods for various molecular contaminants on semiconductor production lines. |
vol.48-5(2011/1/31)
| Current status and future tasks of PM2.5 |
| The health effect due to the fine particles in the atmospheric environment is an important environmental issue over the world. In Japan, the environmental standard for fine particles PM2.5, which is defined by the atmospheric particles under the 2.5 μm of the aerodynamic diameter, has been notified in September, 2009. First, this paper gives an outline of the definition and characteristics of PM2.5 and summarizes the environmental level, annual trend, and chemical composition of PM2.5 in Japan. Second, this paper introduces two kinds of model, receptor model and simulation model, for prediction and analysis of PM2.5 and then demonstrates the example of estimation of source apportionment of PM2.5 in the summer season in the Kanto area, Japan, using the models. Additionally, the influences of transboundary air pollution from Asian continent on the PM2.5 in Japan are discussed. Finally, the future tasks for understanding of current status and formation mechanism of PM2.5 are presented. |
| PM2.5 in the Tokyo metropolitan area |
| The environmental air-quality standard for fine particles (PM2.5) has been established in 2009. Outline of investigations for fine particles in the Tokyo metropolitan area was introduced in this paper. As the decreasing tendency of fine particles has been observed for the last several years, the concentration of fine particles has been improved to a near level of the environmental standard in a general environment. On the other hand, the proportion of chemical component relation to the secondary aerosol such as sulfate ion is high. Therefore, it might be difficult to consider further decrease of fine particles. |
| Production and Source of PM2.5 --Chemical Compositions and Source Apportionment Methods-- |
| Fine particulate matter (PM2.5) is a well known air pollutant which is clearly associated with adverse health effects. Numerous studies have documented the associations between high ambient PM2.5 concentrations and a wide variety of cardio-respiratory health concerns, including lung cancer and premature mortality. The development of effective air quality standard in Japan has been heretofore impeded by a lack of knowledge about the sources and composition of PM2.5 in our country. Furthermore, the existing dataset on PM2.5 consists of mass concentration only, thus giving very limited clues about the PM2.5 pollution origin. Chemical analysis of PM2.5composition quantifies chemical tracers, the knowledge of which helps estimate different PM2.5 source contributions and thereby also provides new insight into the development of effective control PM2.5 measures. This review summarize a significant contribution to the scientific knowledge of PM2.5 composition in ambient air. |
| Measurement method of atmospheric fine particle (PM2.5) |
| PM2.5 measurement methods are both a gravimetric method by a Low-volume air sampler and automated continuous measurement method. The gravimetric method is adopted as a reference measurement method in Japan. Constant mass under 21.5±1.5℃ and 35±5% is necessary for the weighing of filter used in the gravimetric method. Also, the filter is required to keep within ±5℃ to ambient temperature during collecting of sample and until removing. The result of automated continuous measurement monitors are required to equivalent to those of the reference measurement method, and that used several methods; i.e. the beta ray attenuation method, the tapered elements oscillation method and the light scattering method, etc. The devices include a dehumidifier to prevent moisture uptake to particulate. A parallel test between the standard measurement method and the automated continuous measurement monitor was carried out at both urban and suburban sites in both summer and winter. The equivalent evaluation has been performed based on a sampling inspection. |
| Health effects of PM2.5 from view points of toxicology |
| Toxicological effects of particulate matters less than 2.5μm (PM2.5) were evaluated by the recent and previous literatures, in which inhalation exposure or intratracheal instillation of concentrated ambient particles, diesel exhaust particles, residual oil fly ash, carbon particles, or metals etc. was applied in the experimental animals with or without complications including bronchial asthma, respiratory infection, and ischemic heart diseases. Effects of PM2.5 are predominantly shown on cardiorespiratory and / or immunological systems. There appeared to be susceptible conditions to the health effects of PM2.5. At present, however, critical factor(s) responsible for the health effects remain unknown. |
| Air Quality Standards for PM2.5 |
| On September 9, 2009, air quality standards for fine particulate matter (PM2.5) were set in Japan, 24-hour standard at 35μg/m3 and annual standard at 15μg/m3. Air quality standards for PM2.5 were first set in the United States in 1997 based on epidemiological studies indicating that short-term and long-term exposure to PM2.5 is related to premature mortality even in the areas attaining air quality standards for particulate matter. However, at that time, there was criticism that scientific basis of the standards were weak because there were only a few studies using PM2.5 as an indicator. Since then, many epidemiological and toxicological studies were carried out world wide, and the scientific bases were strengthened. Based on this, US tightened the standards in 2006. WHO issued guideline value for PM2.5 in 2007. EU set up limit value and target value for PM2.5 in 2008. In this paper, nature, level and the bases of the air quality standards in the US, EU, WHO and Japan are described with some explanation of epidemiological evidence. |
| What is the novel influenza? |
| In the spring of 2009, the swine-origin H1N1 influenza A virus emerged in Mexico and spread around the world within a few months, resulting in the first influenza pandemic of the 21st century. In Japan, this novel H1N1 virus was first detected on 9 May, 2009 and eventually spread throughout the entire country. In the last century, we experienced three influenza pandemics. The so-called Spanish flu was caused by an H1N1 virus and was responsible for 20 to 40 million deaths in 1918-1919. Other less deadly pandemics occurred in 1957 (Asian flu, H2N2), and in 1968 (Hong Kong flu, H3N2). Pandemics have occurred with 10- to 40-year intervals as novel influenza A viruses emerged that had not previously or recently circulated among humans. Here, I review what we have learned from the novel influenza pandemic. |
| Measuring technology of micro-vibration, electrostatics and magnetic field fluctuation |
| Fluctuation of manufacture environment exert great influence on the semiconductor production processes. Temperature, humidity, cleanliness (particle and gaseous contaminant), micro-vibration, electrostatics, and magnetic field fluctuation are the main elements of the manufacture environment which was mentioned above. In this lecture, the outline of the influence and measurement technology are explained about three of the latter. |
vol.48-6(2011/3/31)
| Research trend for airborne particle in indoor air |
| This paper reported about the indoor air quality for airborne particles, especially ultrafine particles. Firstly, the changes in indoor pollutants from the past to the future were discussed thorough the previous studies. The molds and allergen contaminations in dampness buildings would become a serious problem in the future. Secondary, ultrafine particles were pointed out as the future contaminants in indoor environments. The emission source of ultrafine particles in indoor environments were shown, such as the penetration from outdoor air, emission from photocopiers and laser printers, and secondary organic aerosols reacted from volatile organic compounds. The further researches for ultrafine particles in indoor air are expected to clarify the health effect. |
| Measurement Method for Airborne Microorganism |
| Traditional method for measuring airborne microbes is based on two procedures called sampling and incubation. Sampling normally involves drawing a sampler from an air stream or room by means of instruments based on 3 type's collecting-method, which named impaction, liquid impingement and filtration. Incubation of agar plates typically requires several days. Though the traditional methods can identify the species of microorganisms, they can't obtain any information about suspended viable particles in real time. On the other hand, recently, outbreaks of microbial infections and measures of bioterrorism have been the subject of social attention. The technology for real time detection of the presence of suspended viable particles was developed. This paper reports both the actual conditions and the ISO's newest trend of measurement method for airborne microbes. |
| Measurement of Indoor Allergens |
| "Allergy" is a disease of immune system that cause an overreaction to foreign protein called allergen that is eaten, breathed or injected. House dust mite, animal dander, fungus, pollen and wheat flour derived from food are important sources of allergens in the indoor environment. Especially mite allergens are strongly associated with the pathogenesis of asthma, allergic rhinitis, and atopic dermatitis. It has been reported many studies on control and avoidance of environmental allergens. Major air borne allergens in indoor environments can be measured with immunoassay using allergen-specific antibodies. The small amount of the allergens trapped by air sampler can be measured with a highly sensitive immunoassay. It is hoped that this review article will be useful for studies on environmental allergens and the quality of life for allergic patients against environmental allergens. |
| Mycotoxins and their producers contaminating indoor environment |
| This review focuses on the effects from the exposure to harmful secondary metabolites, mycotoxins, and their mold producers in the indoor environment, associated with human health hazards. Previously, researchers considered that harmful problems occurring in indoor environments contaminated with mold were mainly fungal infection or allergic responses to fungi. However, attention to mycotoxicosis is increasing. This is due to an increase in the number of studies reporting that mycotoxin producers were detected in indoor environments where human health hazards occurred and which reported methods to detect and measure a small amount of mycotoxins in environments. Mycotoxins are taken into the body via ingestion, direct skin contact and inhalation. Although there are many reports about human health hazards caused by ingestion of mycotoxins, only little data on inhalation of myxotoxins via their inhalation in indoor environments. In this paper, we briefly overview some noteworthy molds which are sporulating mold often detected on building materials and in the air, and the mycotoxins they produce : (1)Stachy-botrys chartarum and macrocyclic trichotecene mycotoxins, (2)Aspergillus fumigatus and gliotoxin, (3)Aspergillus versicolor and sterigmatocystin, (4)Chaetomium globosum and chaetoglobosin, (5)Fusarium solani and cyclosporin, (6)Fusarium spp. and T-2 toxin. |
| Problems and Prospects of the Most Advanced Semiconductor Cleaning --Ultraclean Water-Related Problems and Waterless Cleaning Challenges-- |
| With semiconductor-device geometry shrinking and becoming more complex, conventional aqueous cleaning and subsequent drying as well as the nature of ultrapure water for the cleaning tends to cause several serious problems in modern semiconductor manufacturing. These problems will be briefly reviewed, which include cross-contamination of new materials, static charge generation during cleaning, watermark formation after drying, metal dissolution/corrosion in water, and damage to fragile nano-structures due to the high surface tension of water and/or the physical forces of megasonic agitation and atomizing jet spray. Then the solutions to all of these problems will be discussed. Finally, as the ultimate solutions, waterless cleaning techniques are described and discussed, including HF vapor cleaning, cryogenic nitrogen aerosol cleaning, supercritical carbon-dioxide cleaning, and pinpoint cleaning such as nano-tweezers pickup. |
| Analysis of Ultrapure Water |
| Along with shrinkage of LSI geometries, higher quality of ultrapure water has been continuously required, and extremely high quality of ultrapure water has been realized and utilized in LSI production. High quality of ultrapure water can be proved only by high sensitive and high reliable analytical technology for trace impurities such as metallic elements, ions, organics and particles. In this paper, most advanced analytical technologies for impurities in ultrapure water will be described and new water quality evaluation technology using silicon wafers will also be introduced. |
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