scholarly journals Airflow Fluctuation from Linear Diffusers in an Office Building: The Thermal Comfort Analysis

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4808
Author(s):  
Marek Borowski ◽  
Rafał Łuczak ◽  
Joanna Halibart ◽  
Klaudia Zwolińska ◽  
Michał Karch
Keyword(s):  
Energy Consumption ◽  
Quality Parameters ◽  
Office Building ◽  
Air Velocity ◽  
Measuring Point ◽  
Average Value ◽  
Heat Loads ◽  
Selection Of ◽  
Occupied Zone

In buildings, the HVAC systems are responsible for a major part of the energy consumption. Incorrect design or selection of the system and improper installation, operation, and maintenance of the systems’ elements may result in increased energy consumption. It is worth remembering that the main aim of the appropriate system is to maintain the high quality of the indoor environment. Appropriate selection of the HVAC solution ensures both thermal and quality parameters of the air, independently of the internal and external heat loads. The microclimate of a room is affected not only by air temperature, humidity, and purity, but also by air velocity in the occupied zone. The proper air velocity distribution prevents discomfort, particularly at workstations. Based on the measurements in the office building, an analysis of velocity profiles of air supplying two different types of linear diffusers was carried out. The analysis was made based on the results of measurements performed with thermoanemometers in the actual facility. During the study, temperature of the supply air was lower that the air in the room. Analysis was focused on the airflow fluctuation and its impact on the users’ comfort. This is an obvious topic but extremely rarely mentioned in publications related to air diffusers. The results show the importance of air fluctuation and its influence on the users’ comfort. During the measurements, the instantaneous air velocity for one of the analyzed types of the diffuser was up to 0.34 m/s, while the average value from the period of 240 s for the same measuring point was relatively low: it was 0.19 m/s. Only including the airflow variability over time allowed for choosing the type of diffuser, which ensures the comfort of users. The measurements carried out for two linear diffusers showed differences in the operation of these diffusers. The velocity in the occupied zone was much higher for one type (0.36 m/s, 3.00 m from diffusers) than for another one (0.22 m/s, 5.00 m from diffusers). The improper selection of the diffuser’s type and its location may increase the risk of the draft in the occupied zone.

scholarly journals QUALITY OPTIMIZATION OF THE MACHINED SURFACE IN TERMS OF ELECTRIC ENERGY CONSUMPTION IN THE WEDM PROCESS

2021 ◽  
Vol 2021 (2) ◽  
pp. 4400-4407
Author(s):  
LUBOSLAV STRAKA ◽  
◽  
PATRIK KUCHTA ◽  
Keyword(s):  
Energy Consumption ◽  
Production Process ◽  
Electric Energy ◽  
Quality Parameters ◽  
Machining Process ◽  
Discharge Energy ◽  
Machined Surface ◽  
Electric Energy Consumption ◽  
Wedm Process

Current engineering production is characterized by ever-increasing requirements for the final quality of products. But high fabrication productivity is required in many cases as well. Another advantage is, of course, a beneficial economic efficiency of the production process. However, despite the advanced technical level of production and extensive knowledge in the field of electro-erosive machining, in many cases, the overall efficiency of the production process is based on the skills of operators. Besides, insufficiently experienced production operators sometimes still use the trial and error system, even today. A comprehensive set of information for selecting optimal conditions of the electric discharge machining process with the possibility of practical application in real conditions of practice is currently non-existent. The paper therefore describes the experimental measurements performed in order to optimize the quality of the machined surface with respect to electric energy consumption in the WEDM process. In contrast to current approaches, the solution of the issue relied on determining the relationship between the performance parameters of the process and its controllable output quality parameters so that they would be applicable to the conditions of real practice. It was found that with the reduction of discharge energy through individual WEDM operations, the quality indicators in terms of roughness parameters improve. However, on the other hand, reducing the discharge energy leads to a significant increase in the total electric energy consumption. Therefore, the aim of the performed optimization was to look for a suitable type of WEDM operation, in which a favourable value of the roughness of the eroded surface is achieved while maintaining favourable electric energy consumption.

scholarly journals Selection of parameters during shredding of corn stalks as an additive to the polymer

2021 ◽  
Vol 1199 (1) ◽  
pp. 012061
Author(s):  
M Macko ◽  
D Łączny ◽  
J Lewandowski
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Low Energy ◽  
Grinding Speed ◽  
Low Energy Consumption ◽  
Design Variant ◽  
Cylindrical Holes ◽  
Processing Steps ◽  
Selection Of

Abstract This paper presents the results of research on the process of grinding dried corn stalks to use them as polylactide filler. Shredding was carried out on a laboratory shredder with the use of a design variant based on discs with cylindrical holes. By selecting the design variant, the appropriate grinding speed and the material pressure on the shredder discs, the most favourable parameters in terms of the quality of the shredded product and low energy consumption were selected. The research was conducted to reduce the energy demand during the shredding process and to obtain the shredded material suitable for further processing steps.

scholarly journals A multi-factorial mathematical model for the selection of electropolishing parameters with a view to reducing the environmental impact

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paweł Lochyński ◽  
Sylwia Charazińska ◽  
Maciej Karczewski ◽  
Edyta Łyczkowska-Widłak
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Stainless Steel ◽  
Current Density ◽  
Quality Parameters ◽  
Important Goal ◽  
Process Duration ◽  
Metal Processing ◽  
Selection Of

AbstractElectrochemical metal processing is a process that generates harmful pollution. An important goal often disregarded by researchers is not only the achievement of the best possible quality of electropolished surface, but also minimising the load of metal ions in the wastewater generated in the process. The conducted experiments on the electropolishing of stainless steel in laboratory conditions, varied time, temperature and current density conditions, as well as process bath contamination (ranging from 0 to 6% Fe mass) allowed us to develop a multi-factorial mathematical model. This model offers the possibility of being able to select the process parameters recommended for achieving the desired effects. It takes into account such surface quality parameters as roughness and gloss, process duration and current density that determine power consumption, as well as the weight loss of the electropolished element that influence the rate of contamination in processing baths and wastewater. The study presents the composition of a passive film of stainless steel after the electropolishing process at the initial and final stages of the process bath’s exploitation. The results obtained from XPS tests were then correlated with the results of corrosion tests and resistance to pitting corrosion in the environment of 0.1 M NaCl.

scholarly journals Методика комплексної оцінки кнурів і свиноматок за якістю потомства

2017 ◽  
pp. 59-62
Author(s):  
С. Л. Войтенко
Keyword(s):  
Comprehensive Evaluation ◽  
Uniform Method ◽  
New Method ◽  
Evaluation Index ◽  
Average Value ◽  
Selection Of

Висвітлені основні підходи до комплексної оцінки кнурів і свиноматок за якістю потомства в умовах ферми (господарства). Запропоновано визначати цінність кнурів і свиноматок не лише за  відгодівельними і м’ясними ознаками їх потомків, але й за власною продуктивністю останніх.  Описано послідовність добору тварин для їх випробовування в умовах ферми за власною продуктивністю та відгодівельними і м’ясними ознаками з визначенням балу за кожну із ознак. Для комплексної оцінки кнурів і свиноматок за якістю потомства запропоновано використовувати розроблений оціночний індекс,  в основі якого середня величина усіх досліджуваних під час випробовування ознак у сибсів і напівсибсів. Запропонована нова методика оцінки кнурів і свиноматок за якістю потомства дасть змогу оцінити не лише племінних свиней, але помісних і гібридних,  застосовувати єдину методику оцінки тварин основного стада у господарствах різної категорії, обходитися без станцій контрольної відгодівлі свиней та визначити цінність кнура і свиноматки за якістю потомства на основі розробленого оціночного індексу. The main approaches to the integrated evaluation of boars and sows on the quality of offspring in the conditions of a farm (farm) are covered. It is offered to determine the value of boars and sows not only on the fattening and meat characteristics of their offspring, but also on their own productivity of the latter. The sequence of selection of animals for their testing in conditions of the farm according to their own productivity, fattening and meat characteristics with a score for each of the characteristics is described. For a comprehensive evaluation of boars and sows on the quality of offspring offered to use the developed evaluation index, which is based on the average value of all the tests for testing the characteristics of descendants. Offered new method for estimating boars and sows on the quality of offspring will make it possible to estimate not only breeding pigs but hybrid and local ones, to apply a uniform method for estimating the animals of the main herd in farms of different categories, to dispense with pigs' control stations and determine the value of boars and sows in the quality of offspring based on the developed evaluation index.

scholarly journals KAJIAN MUTU BAKSO IKAN TUNA YANG DISUBSTITUSI TEPUNG KARAGENAN

2020 ◽  
Vol 8 (1) ◽  
pp. 30
Author(s):  
Moon Ayu Kawanari Sitepu ◽  
Hanny Welly Mewengkang ◽  
Daisy Monica Makapedua ◽  
Lena Jeane Damongilala ◽  
Eunike Louisje Mongi ◽  
...  
Keyword(s):  
Water Content ◽  
Quality Parameters ◽  
Plate Count ◽  
Average Value ◽  
Randomized Design ◽  
Fish Product ◽  
Storage Times ◽  
And Storage ◽  
Total Bacteria

Fishball is a fish product that knows for their distinctive taste and chewy texture. The quality of fishball greatly affects the attractiveness of consumers to consume it, regarding the taste and aroma. The ingredients of fishball that have properties as an emulsifying is  carrageenan. The purpose of this study was to determine the quality of tuna fishballs substituted with carrageenan flour with different concentrations and storage times. The treatment design used was RAL (completely randomized design) which consisted of 4 different concentration treatments of added carrageenan, for 0%, 1%, 2% and 3% with 2 days of storage and 2 times repetition. The quality parameters were organoleptic test, water content, pH and TPC (Total Plate Count). The results showed that the addition of carrageenan affected the water content and pH of fishballs. Tuna fishballs with the addition of a concentration of 2% are the best products with an average value of organoleptic values: 6.58; water content: 71.63; pH: 5.46; and TPC: 2.6 × 10 4. Water content in fishballl is not met SNI quality requirements. Total bacteria (TPC) in fishballs met SNI quality requirements.Keywords: tuna fishballs, carrageenan

scholarly journals Pelletization of Biomass Feedstocks: Effect of Moisture Content, Particle Size and a Binder on Characteristics of Biomass Pellets

2021 ◽  
Author(s):  
Imran Ahmed ◽  
Asif Ali ◽  
Babar Ali ◽  
Mahdi Hassan ◽  
Sakhawat Hussain ◽  
...  
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Particle Density ◽  
Value Added ◽  
Quality Parameters ◽  
Heating Value ◽  
Furfural Residue ◽  
Pellet Density

Abstract Pelletization of low value added biomass materials such as furfural residue (FR) and sawdust was performed by using a lab scale pelletizer. Effects of moisture content (MC), particle size and a binder on quality parameters (e.g. pellet density, strength and hardness) and on energy consumption were investigated. Quality of pellets was analysed and compared. MC was found to be the more dominant parameter affecting pellet density, strength and hardness of furfural residue pellets (FRPs) and sawdust pellets (SPs), followed by particle size and a binder. Highest particle density of 1.419 g/cm3 for FRPs (0.5–1.41 mm) and 1.243 g/cm3 for SPs (0.25–0.5 mm) was achieved at MC of 8% and 18%. Highest decrease in relaxed density was observed at MC of 13% for FRPs and 28% for SPs. True density of FRPs and SPs made from particles of 0.25–0.5 mm was found higher than 0.5–1.41 mm. The highest strength and hardness (6.29 MPa and 401.3 N/mm2) for FRPs was achieved at 5.5% MC and particles 0.25–0.5 mm. Optimum strength (6.03 MPa) and hardness (96.06 N/mm2) for SPs was obtained at 18% MC and particles 0.25–0.5 mm. The lowest energy consumption (16.16 J/g) for FRPs (0.25–0.5 mm) and 20.22 J/g for SPs (0.5–1.41 mm) was achieved at MC of 13% and 28%. Addition of binding agent to FR sawdust decreased energy consumption of FRPs and SPs. SPs quality was enhanced with the use of a binder. Heating value of FRPs were found higher than SPs.

scholarly journals A comparative analysis on water quality in an urban micro watershed

2017 ◽  
Vol 28 (4) ◽  
pp. 566-578 ◽  
Author(s):  
Karen Tavares Zambrano ◽  
Cristiano Poleto ◽  
Jefferson Nascimento Oliveira
Keyword(s):  
Water Quality ◽  
Comparative Analysis ◽  
Quality Parameters ◽  
Quality Data ◽  
Water Quality Data ◽  
Content Type ◽  
Quality Water ◽  
Practical Implications ◽  
Selection Of

Purpose This study presents a comparative analysis of water quality data in an urban micro watershed to study the magnitude of impacts on the water quality parameters over the last decade. The purpose of this paper is to evaluate the degree of deterioration using the water quality index. Design/methodology/approach Rapid urban growth without proper land use and occupation planning results in the overload of urban water resources. Therefore, a literature review was conducted on the research subject published in the dissertation databases of the Engineering Faculty of Ilha Solteira, which resulted in the selection of two dissertations on water quality in the Ipê Stream, Ilha Solteira – SP, Brazil. The results will be evaluated according to the Brazilian laws and regulations in force. Findings This study shows that pollution and degradation in the stream intensified during the study period, with the most impacted areas within the urban perimeter. Practical implications The increasing impacts underscore the need for efficient measures such as implementation of retention reservoirs, elimination of clandestine sewage connections and restoration of riparian forests. Originality/value This study highlights the need to monitor the water quality of streams in order to establish preventive and mitigating measures to avert the growing environmental impacts and to ensure quality water for future generations.

scholarly journals Life Cycle Analysis of Operational Energy in Office Projects Toward Sustainability Practices in the Malaysian Construction Industry

2018 ◽  
Vol 7 (3.7) ◽  
pp. 39
Author(s):  
Farzaneh Moayedi ◽  
Noor Amila Wan Abdullah Zawawi ◽  
Mohd Shahir Liew
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Office Building ◽  
Dominant Factor ◽  
Sustainable Solutions ◽  
Operational Energy ◽  
Building Components ◽  
Heat Exchanges

Global warming mitigation is used as a requisite key to promote approaches and sustainable policies in developing countries that aim to minimize the level of carbon emission in built environment. In the past few years, energy demand has grown enormously in Malaysia. CO2 emission from energy consumption, mainly from electricity is a stark condemnation of commercial sector. Building operational energy particularly the thermal aspect, is the dominant factor that used to be highlighted and investigated due to the fact that it is the main proportion of operational energy consumption in buildings. The rate of energy dissipation in building components depends on design and environmental conditions. Accordingly, actions need to be taken in order to promote the quality of buildings in terms of heat exchanges, which can lead to a significant energy saving. Using of appropriate thermal insulation is effective way to diminish greenhouse gas emissions by reducing energy consumption. Therefore, the aim of the study is to investigate and determine the total amount of energy consumption from an office building. For reliability purposes, energy consumption from operation of baseline building was compared with the eco-friendly existing office building. Results show that, after implementation of sustainable solutions in the case study, operational energy consumption was successfully reduced to a grate extend. 

scholarly journals Parameters of production and quality of new cultivars of perennial leguminous plants as livestock feed

2005 ◽  
Vol 21 (3-4) ◽  
pp. 89-96
Author(s):  
Zorica Tomic ◽  
Zorica Nesic ◽  
Vesna Kmjaja ◽  
Miroslav Zujovic
Keyword(s):  
Red Clover ◽  
Common Species ◽  
Quality Parameters ◽  
Livestock Feed ◽  
Second Year ◽  
Perennial Legumes ◽  
New Cultivars ◽  
Selection Of ◽  
Better Than

This paper presents the results obtained in testing of new selection of four most important and most common species of legumes used for animal feeds in Serbia. Alfalfa, red clover, bird's trefoil and sainfoin are also high quality plants regarding both nutritive substances and yield of dry matter. We have investigated three new selections of alfalfa, two selections of red clover, two selections of bird's trefoil and one of sainfoin in relation to standard ones. Trial lasted two years (2003-2004), designed according to standard methods for testing and recognition of new sorts. The production of green mass through four cuts per year was determined, together with the variation coefficient among cultivars. In the cuts of the second year the quality parameters were determined by standard lab analyses. The content of protein in all three new selections of alfalfa was higher in relation to standard (16,01%). while the standard of red clover with 20,03% was better than new selection. New selections of bird's trefoil are of better quality than standard (22,08 %), which is the case also with sainfoin (19,71 %). On the basis of obtained production and quality parameters the assortment of perennial legumes will be enriched by new cultivars.

scholarly journals Quality Assessment of Soil Pollution Monitoring: Focus on Representativeness

2016 ◽  
Vol 5 (1) ◽  
pp. 51
Author(s):  
Andre Desaules
Keyword(s):  
Quality Assessment ◽  
Quality Criteria ◽  
Quality Parameters ◽  
Soil Sampling ◽  
Pollution Monitoring ◽  
Soil Monitoring ◽  
And Control ◽  
Practical Recommendations ◽  
Selection Of

<p>Soil monitoring data can be no better than the quality of the monitoring system they stem from. Quality assessment (QA) of soil monitoring requires reliable and comprehensive quality assessment and quality control (QA/QC) schemes including (1) the selection of parameters and measurement quality related to (2) space and (3) time. It can be presented by a synoptic diagram with three axes based on a table with quality criteria. The two major quality parameters are the degrees of resolution (precision) and representativeness (bias), whereas the latter does not yet include parameter selection and soil sampling.<strong> </strong><strong></strong></p>As a result the quality of soil monitoring is usually greatly overestimated. This finding is supported by examples and practical recommendations are given. Since full representativeness for the three aspects of soil monitoring is a fiction in practice, their biases have to be quantified completely, continuously and reliably. The most important challenges are to quantitatively assess and control the representativeness of primary soil sampling and to improve it.

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