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.

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.

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.

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,

Air purifier or fresh air system?A comparison of energy consumption and cost in urban China residential buildings

Chinese urban residential buildings face serious indoor air quality problems.Air purification systems(e.g.,air purifiers,fresh air systems)that supply fresh air or purify indoor air are widely used in residential buildings to improve indoor air quality.Considering the challenges of energy conservation and emission reduction,it is urgent to guide residents on choosing appropriate air purification systems.The key problem is how to identify the best air purification system with the lowest energy consumption or operating cost.Comparisons of air purification systems have rarely been conducted on the premise that they should deliver air such that the main indoor pollutant concentrations all meet air quality standards.Also ignored in comparisons are the increased filtration resistance caused by dust accumulation on the filter and the cost of filter replacement.In this study,we propose a method to compare residential air purification systems based on energy consumption and total cost,and we provide methods to select air purification systems in China's different climatic regions.We used a standard two-person bedroom as the example,and determined the most suitable(minimum cost or energy consumption)air purification systems for the capital cities of the provinces in Chinese mainland.

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.

Inbreeding and genetic load in a pair of sibling grouse species:Tetrastes sewersowi and T.bonasia

Genetic load and inbreeding are recognized as important factors to be considered in conservation programs.Elevated levels of both can increase the risk of population extinction by negatively impacting fitness-related characters in many species of plants and animals,including humans(inbreeding depression).Genomic tech-niques are increasingly used in measuring and understanding genetic load and inbreeding and their importance in evolution and conservation.We used whole genome resequencing data from two sibling grouse species in subarctic Eurasia to quantify both.We found a large range of inbreeding measured as FROH(fraction of runs of homozygosity)in individuals from different populations of Chinese Grouse(Tetrastes sewerzowi)and Hazel Grouse(T.bonasia).FROH estimated from genome-wide runs of homozygosity(ROH)ranged from 0.02 to 0.24 among Chinese Grouse populations and from 0.01 to 0.44 in Hazel Grouse.Individuals from a population of Chinese Grouse residing in the Qilian mountains and from the European populations of Hazel Grouse(including samples from Sweden,Germany and Northeast Poland)were the most inbred(FROH ranged from 0.10 to 0.23 and 0.11 to 0.44,respectively).These levels are comparable to other highly inbred populations of birds.Hazel Grouse from northern China and Chinese Grouse residing in the Qinghai-Tibetan Plateau showed relatively lower inbreeding levels.Comparisons of the ratio between deleterious missense mutations and synonymous mutations revealed higher levels in Chinese Grouse as compared to Hazel Grouse.These results are possibly explained by higher fixation rates,mutational melt down,in the range-restricted Chinese Grouse compared to the wide-ranging Hazel Grouse.However,when we compared the relatively more severe class of loss-of-function muta-tions,Hazel Grouse had slightly higher levels than Chinese Grouse,a result which may indicate that purifying selection(purging)has been more efficient in Chinese Grouse on this class of mutations.

The Design of an Air Rower That Can Purify Indoor Air

To solve the problem that utilizing an air rower lowers indoor air quality due to the dust stirred up in the course of rowing, an air rower is designed to have the extra function of air purifying. The designed rower is composed of six parts, which are the frame, air generator, transmission part, air purifying filter cartridge, performance monitor, and electric motor. To fulfill the task, the filter cartridge is vertically arranged to lead the air to enter from the lower part and vent out of the upper part to filter and purify the air before it enters the generator so as that the indoor air is well circulated to improve the air purification effect when the rower is utilizing. The modular detachable design allows the air filter and electric motor to be installed and disassembled to adapt to different air purification needs. The designed rower has the benefit of lower purchasing cost and energy saving that may motivate exercising, bringing more fun and the sense of accomplishment.

Isolative Synthesis and Characterization of Cellulose and Cellulose Nanocrystals from Typha angustifolia

The application potential of cellulosic materials in natural composites and other fields needs to be explored to develop innovative, sustainable, lightweight, functional biomass materials that are also environmentally friendly. This study investigated Typha angustifolia (Typha sp.) as a potential new raw material for extracting cellulose nanocrystals (CNCs) for application in wastewater treatment composites. Alkaline treatments and bleaching were used to remove cellulose from the stem fibres. The CNCs were then isolated from the recovered cellulose using acid hydrolysis. The study showed a few distinct functional groups (O-H, -C-H, =C-H and C-O, and C-O-C) in the Fourier Transform Infrared (FTIR) spectra. A scanning electron microscope (SEM) revealed the smooth surface of CPC and CNCs, which resulted from removing lignin and hemicellulose from powdered Typha angustifolia. Based on the crystalline index, the powdered Typha angustifolia, CPC, and CNCs were 42.86%, 66.94% and 77.41%. The loss of the amorphous section of the Typha sp. fibre resulted in a decrease in particle size. It may be inferred from the features of a Typha sp. CNC that CNCs may be employed as reinforcement in composites for wastewater treatment.

Molecular Evolutionary Analysis of DFR Gene in Lamiidae Plants

[Objective]The aim of this study was to reveal the molecular evolutionary characteristics of dihydroflavonol 4-Reductase（DFR）—a key enzyme in anthocyanin synthesis pathway in Lamiidae plants.[Method]Based on DFR amino acid and cDNA sequences released by NCBI,molecular evolution of DFR gene was analyzed with bioinformatic software.[Result]Seventeen plants fell into two major branches,Lamiidae and Liliidae.Most of the plants within a same family cluster assembled together,which basically accords with the morphological development of species.Prediction results based on selection pressure using MEGA,DNAsp and PAML software showed that DFR gene in Lamiidae plants underwent strong purifying selection pressure.[Conclusion]Our results laid basis for analyzing the molecular mechanism of enzymatic characteristics of DFR and of the anthocyanin synthesis pathway.

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 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.

Preparation of Purified and Inactivated HP-PRRS Vaccine

[Objective] The aim of this study was to improve the purification and protective potency of HP-PRRS inactivated vaccine. [Method] HP-PRRS virus that had been multiplied inside Marc-145 cells was collected and concentrated 50 times and then inactivated. Complete virions were separated and collected by chromatography with Sepharose 4 Fast Flow. Oil adjuvant was added to prepare purified inactivated vaccine. [Result] Viral protein was separated from other proteins by purification and the viral protein contents ranged from 76.7% to 82.4%, and 96% of the expected serum proteins were removed. Protective potency of purified vaccine was above 4/5 and positive conversion rate of antibody was over 86%, both higher than that of unpurified vaccine. The differences were significant. [Conclusion] The experiment il-lustrated that the immune efficacy of vaccine can be enhanced through concentrat- ing and purifying, while the non-viral protein can be removed, so that allergic reaction and stress response cadsed by vaccine inoculation can be avoided.

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.

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。