Experimental Study on Purification Efficiency of Air Purifier for the Indoor Total Volatile Organic Compounds

By using total volatile organic compounds （TVOC） as the objective volatile pollutant, the purification efficiency of some representative air purifiers bought in the market was determined under the relatively independent and stable environmental conditions supplied by the self-made multi- functional environmental test chamber. Various evaluation parameters of TVOC were calculated based on the tested results, such as purification ef- ficiency and removal rate. The results showed that the TVOC purification efficiency increased with enhancing the temperature or lessening the rela- tive humidity, but this effect is not obvious. The air purifiers which use photocatalytic technology have higher TVOC purification efficiency than those which only use some adsorption technology. The purification efficiency and removal rate can be more accurate to evaluate the purification efficiency of air purifiers.

Practical Mitigation Strategies for Countering the Spread of Aerosolized COVID-19 Virus (SARS-CoV-2) Using Ventilation and HEPA Air Purifiers: A Literature Review

This paper assesses, through an extensive literature review, the use of ventilation and High-Efficiency Particulate Air (HEPA) purifiers as practical mitigation strategies for reducing the spread of aerosolized COVID-191 virus. HEPA is a well-defined standard by the U.S. Department of Energy for filters. The focus of the literature review was on indoor air quality (IAQ) and COVID-19, with a particular emphasis on classroom settings. The start of the review, January 2020, was chosen to coincide with the first cases of COVID-19 in North America. Although children under the age of 12 are currently not yet vaccinated, there is mounting pressure for a return to normal by the start of the new school year, 2021. Also, many classrooms lack pre-installed mechanical ventilation systems (Olsiewski et al., 2021);therefore, mitigation in classrooms often falls solely in the hands of teachers and students. Research shows that ventilation and air purification are essential tools to counter aerosolized transmission (<5 μm) of the COVID-19 virus. According to Curtius et al. (2020), the inhaled dose of particles containing virus RNA is six times lower when using air purifiers with an ACH (air changes per hour) of 5.7. However, ventilation and air purifiers are not replacements for masks, which remain vital for countering droplet (>5 μm) transmission. In addition, occupancy (i.e., number and proximity of people present in a given area) and group activity levels (e.g., talking, shouting, singing) play a critical role in viral transmission. Although natural ventilation by opening windows can be an essential strategy to help counter the spread of the virus, the level of ventilation offered by opening windows is largely uncontrollable as it is subject to weather conditions and building design. One must also consider the energy implications (i.e., loss of heat) that this strategy carries. Scientific evidence shows that varying levels of continuous and/or intermittent ventilation, either mechanical or natural, combined with the use of HEPA air purifiers, can provide a higher degree of protection than window access alone (Curtius et al., 2020). Systematic deployment of a hybrid mitigation strategy incorporating both ventilation and HEPA air purification in schools, offices, or other facilities offers a practical way to establish a safe re-opening of society in Canada.

Potential in the Chinese Air Purifier Market

Since 'haze' became a hot word in 2013,the air purifier market has been buoyant.However,as manufacturers gather,the competition is getting fiercer.To promote energy saving and environmental protection,the government provides subsidies to those energy efficient electric appliances based on a list.Last year,air purifiers of some brands were included on this list.

Chang Gao Brand Water Purifier & Mineralizer

People are making excessive demands for their drinking water as they pay more and more attentions to the quality of life. Mineral water contains more calcium, magnesium and lots of trace elements than the running water, and therefore it is good for the digestion, promotion of metabolism, prevention of cardiovascular diseases and osteoporosis, and promotion of Children growth. It has become a favourite drink for many people.

Guanyin Water Purifier

The Beijing Guanyin Water Purifying Technical Co. Ltd. is a manufacturing company, specialized in producing water purifying equipment, with water purifying technology imported from the United States and its combination of specific resources from China. The said company produces Guanyin water purifier which is a kind of renovated and high efficiency family water purifier of the water tap type. It is fitted with dual water outlets and a multi-stage filtering device, which helps prolong its service life. Different to other makes,

Performance Evaluation of Two Series Vertical Flow Filters for Wastewater Treatment: A Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

This paper evaluates the efficacy of two sequential vertical flow filters (VFF), FV1 and FV2, implanted with Typha, in a pilot-scale wastewater treatment system. FV1 comprises three cells (FV1a, FV1b, and FV1c), while FV2 consists of two cells (FV2a and FV2b), each designed to reduce various physicochemical and microbiological pollutants from wastewater. Quantitative analyses show significant reductions in electrical conductivity (from 1331 to 1061 μS/cm), biochemical oxygen demand (BOD5 from 655.6 to 2.3 mg/L), chemical oxygen demand (COD from 1240 to 82.2 mg/L), total nitrogen (from 188 to 37.3 mg/L), and phosphates (from 70.9 to 14.6 mg/L). Notably, FV2 outperforms FV1, particularly in decreasing dissolved salts and BOD5 to remarkably low levels. Microbiological assessments reveal a substantial reduction in fecal coliforms, from an initial concentration of 7.5 log CFU/100mL to 3.7 log CFU/100mL, and a complete elimination of helminth eggs, achieving a 100% reduction rate in FV2. The study highlights the impact of design parameters, such as filter material, media depth, and plant species selection, on treatment outcomes. The findings suggest that the judicious choice of these components is critical for optimizing pollutant removal. For instance, different filtration materials show varying efficacies, with silex plus river gravel in FV1c achieving superior pollutant reduction rates. In conclusion, VFFs emerge as a promising solution for wastewater treatment, underscoring the importance of design optimization to enhance system efficiency. Continuous monitoring and adaptation of treatment practices are imperative to ensure water quality, allowing for safe environmental discharge or water reuse. The research advocates for ongoing improvements in wastewater treatment technologies, considering the environmental challenges of the current era. The study concludes with a call for further research to maximize the effectiveness of VFFs in water management.

Genomic Mutations Within the Host Microbiome: Adaptive Evolution or Purifying Selection

Next-generation sequencing technology has transformed our ability to assess the taxonomic composition functions of host-associated microbiota and microbiomes. More human microbiome research projects—particularly those that explore genomic mutations within the microbiome—will be launched in the next decade. This review focuses on the coevolution of microbes within a microbiome, which shapes strain-level diversity both within and between host species. We also explore the correlation between microbial genomic mutations and common metabolic diseases, and the adaptive evolution of pathogens and probiotics during invasion and colonization. Finally, we discuss advances in methods and algorithms for annotating and analyzing microbial genomic mutations.

Gas Purification and Quality Control of the End Gas Product

One of the main problems in the flow-through gas purification technologies is related with continuous control of the outlet gas purity. The information concerning purity of the produced gas is on high demand, e.g., for processing systems integrated with gas purifiers. The positive solution of this problem has become possible only now due to the appearance of reactive getters (reactants) that serve as highly efficient sinks for gas impurities and our sorption model of the processes, which take place in gas purifiers with these reactants. According to the given model the appearance of a single valued functional connection between the purity of the gas product and the duration of the treatment of the gas flow by the sorbing powder is typical for any system Me -Y, where Me is a powder reactant and Y is an impurity gas. This strict correlation provides the mathematical justification to a simple method of determining the concentration of the impurity in the gas flow at the exit from the gas purifier. This method comes down to measuring of the quantity of the purified gas by a gas flow meter, the readings of which are graduated in the units of gas concentration.

Evaluation of eco-friendly coagulant from <i>Trigonella foenum-graecum</i>seed

The ability of seed extracts of Trigonella foenum-graecum (T. foenum-graecum) and Cuminum cyminum (C. cyminum) to act as natural coagulants was tested using natural turbid water. Seed extracts were prepared using distilled water and NaCl (0.5 M and 1.0 M) solution. Only 1.0 M NaCl extract of T. foenum-graecum had coagulation capability and did not depend on pH values. Further it showed that natural coagulant obtained from T. foenum-graecum is temperature (upto 100?C) and pH stable (pH 4.0 - 10.0). Extract of C. cyminum had very minimal (16 ± 2) coagulation property. The seed extract of T. foenum-graecum showed about 80% coagulation properties, where as the best known natural coagulants such as Strychnos potatorum and Moringa oleifera, and chemical coagulant such as Al2(SO4)3 showed around 90%, 65% and 95% respectively, which are used as standards for the present study. When compared with pond water, T. foenum-graecum extract treated water shows decrease in alkalinity, turbidity, KMnO4 demand and total coli-form. This study reveals that seed extract of T. foenum-graecum can be used as natural water coagulant.

The Optimal Coexistence of Cells:How Could Human Cells Create The Integrative Physiology

A general view of human physiology is proposed.Each of 220 cell types must provide its intimate functions despite occasional or chronic obstacles created by other cells.The physiological mechanisms are independently emerged and evolutionarily saved due to their ability to provide optimal-like coexistence of cells on a background of destructive challenges of external/internal environments.In certain limits,both cells and organs are adaptive.The cell has accumulated both passive adaptation mechanisms mainly parallel working in the biochemistry,and active physiological mechanisms fighting for the optimal cell metabolism.Its rate depends on the cell type and current phase into the cell cycle.The adaptive properties of organs and their functional systems have resulted from the cells’adaptivity.The impaired cells(under energy lack and/or contaminated cytoplasm)produce adaptation factors acting both in the cell and at multiple organism-scales.Multicellular mechanisms,enhancing the cell fight for energy balance,creating the due cytoplasm for optimizing metabolism,force the most physiological characteristics,including the mean arterial pressure to fluctuate or shift.The view is a basis for re-thinking the concept of the socalled physiological norm and fundamental mechanisms of age-associated pathologies,in particular,hypertension.

Rational Purify在VC++开发中的应用

文章简要介绍了RationalPurify工具在软件开发过程中的作用,描述了Purify在VC++开发程序中的应用步骤。

Chinese New-coined Words Management in P.R.C

The paper relies on the language management model. First of all, the thousands of new words coined each year in China can be roughly divided into eight groups. Besides, it exemplifies the problems that have occurred in communication. Last but not least, to reflect language management acts/processes, it reports the efforts the language authorities and governmental bodies have made in the struggle to solve the problems. It attempts to remind the language management agencies of the point that for the use of new words, the language users are always right as long as communication flows without problems in understanding.

The Newest Getter Technologies: Materials, Processes, Equipment

The efficiency of sorption purification of gases, as measured by an improvement in product quality and/or lowering of its cost, can be significantly increased via simple solutions: the substitution of current getter technology with reactive getters;and stimulation of the material in the sorption process using mechanochemical methods instead of heating or cooling. These ideas were embodied by the authors in new sorption apparatuses and devices such as mechanochemical sorption apparatuses for production of ultra pure gases, improved gas purifiers with reactive sorbent for production of pure and high purity gases and, finally, fluidized bed columns for mass production of pure and high purity gases.

软件测试方法及测试工具应用

介绍了软件测试的过程及方法,重点分析了几种常用软件测试工具的特点及具体应用方法,为软件测试人员根据不同的测试环境选择适用的测试工具提供了依据。

Adsorption Kinetics of Methylene Blue from Aqueous Solutions onto Palygorskite

The adsorption kinetics of methylene blue from aqueous solutions on purified palygorskite was investigated. The kinetics data related to the adsorption of methylene blue from aqueous solutions are in good agreement with the pseudo-second order equation in ranges of initial concentration of 120-210 mg/L, oscillation speed of 100-200 r/min and temperature of 298-328K. The experimental results show that methylene blue is only adsorbed onto the external surface of purified palygorskite, and the apparent adsorption activation energy is 13.92 kJ/mol. The relatively low apparent adsorption activation energy suggests that the adsorption of methylene blue involves in not only a chemical, but also a physical adsorption process, and it is controlled by the combination of chemical adsorption and fiquid-film diffusion.

Enhancement of vitamin A combined vitamin D supplementation on immune response to Bacille Calmette-Guerin vaccine revaccinated in Chinese infants

Objective:To investigate whether there is an association between diameter of bacille CalmetteGuerin(BCG)sears and effect of purified protein derivative(PPD)reaction anil to determine whether vitamin A(VA)combined vitamin I)(VD)supplementation influences the immune response to BCG revueeinated in Chinese infants.Methods:A cross-section and 3-month community-randomised trial was conducted.A total of 5 629 infants at 3,6 and 12 months of age in Junan County of China were examined for BCG scar fonnation.Then,597 revuccinated infants were randomly assigned to supplementation(n=307)and control(n=290)groups.The supplementation group were daily assigned to 1 500 IU VA and 500 IU VD for 3 months.Then all infants were subjected to skin test with PPD.Results:The diameter of BCG sears was positively con-elated with diameter of skin indurations of PPD(r=0.17,P<0.05)in the 5 629 infants.The rate of positive response to PP1)was higher in the supplementation group than in the control group(96.1%versus 89.7%,P<0.05,prevalence ratio 1.07.95%CI 1.02-1.12).The prevalence ralio of PPD response for the supplementation group compared with that for the control group was 1.07(95%CI 1.01-1.13)for the males and 1.08(95%CI 1.00-1.17)for the females.For the supplementation group,the males got larger tuberculin induration than the females[(0.73±0.2l)cm versus(0.67±0.20)cm.P<0.05)after intervention.Conclusions:The diameter of BCG scars was effectively correlated with PPD response,which indicates BCG scar formation may be an useful tool Io evaluate the effect of tuberculosis prevention.VA combined VD supplementation may play an immunoregulatory rale in BCG revuecination.This may contribute to the prevention of childhood tuberculosis.

Recyclable adsorbent of BiFeO_3/Carbon for purifying industrial dye wastewater via photocatalytic reproducible

It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic recyclable adsorbent of BiFeO3/Carbon nanocomposites for purifying simulative industrial dye wastewater. It is found that the structure of the prepared BiFeO3/Carbon nanocomposite is related to the natural structure of the biscuit, annealing temperatures and immersing times, demonstrated by XRD, TEM, UV-Vis and adsorptive activities. Kinetics data shows that the adsorption rate of the adsorbent to the dye is rapid and fitted well with the pseudo-second-order model, that more than 80% of dyes can be removed in the beginning 30 min. The adsorption isotherm can be perfectly described by the Langmuir model as well. It can be seen from the adsorption data that the adsorption performance can reach over 90% at pH ? 2–12, which can imply its universal utilization. The prepared BiFeO_3/Carbon nanocomposites have also displayed excellent capacities(over 90% within 30 min) for adsorption of seven different dyes and their mixed one. According to the five times photocatalytic reproducible experiments, it is proved that BiFeO_3/Carbon nanocomposites show the excellent stability and reproduction for purifying simulative industrial dyes, even the sample have been placed for one year. These research results indicate that the adsorbent BiFeO_3/Carbon can be a suitable material used in treating industrial dye wastewater potentially.

Preparation of 5N high purified indium by the method of chemical purification-electrolysis

The application of indium requires high purity indium as material.5N high purity indium had been prepared by the method of acombination of chemically smelting and electrolysis. Smelting timewas 10 min, the abstraction rate of cadmium was 80/100-90/100 whenused solution of I_2-KI and glycerine to smelt indium. 4N metalindium was used as anode, high purity indium as cathode, In-2(SO_4)_3-H_2SO_4 system as electrolyte, and In content is 100 g/L, pH2-3 and current density 80-100 a/m^2.

Mechanical Properties,Purifying Techniques and Processing Methods of Metal Yttrium

The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced. The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium including extruding, forging, rolling, wiredrawing and welding were also introduced. Finally, the potential use of yttrium and its alloys were prospected.