THEORETICAL STUDY OF THE EFFECT OF GEOMETRICAL PARAMETERS AND LOCATION OF ROTOR IMPACT ELEMENTS OF AN IMPACT-CENTRIFUGAL GRINDER ON SPEED AND ANGLES OF CRUSHED PARTICLES FLIGHT

2020 ◽  
Keyword(s):  
Granulometric Composition ◽  
Theoretical Study ◽  
Process Efficiency ◽  
Geometrical Parameters ◽  
Grinding Process ◽  
Main Work ◽  
Impact Element ◽  
The Impact ◽  
Positive Effect ◽  
Efficiency Indicators

One of efficiency indicators of grain grinders is grain granulometric composition. The basis of mixed fodder is crushed grain, the particles of which must have a leveled granulometric composition for subsequent mixing and obtaining a high-quality feed mixture. In agricultural production, hammer crushers are widely used, in which the destruction of grain occurs due to the impact of a hinged hammer. The main disadvantage of these crushers is that not the entire surface of the hammers is involved in grinding, thus reduces grinding process efficiency. A slightly different principle of material destruction is laid down in the basis of the proposed design of the shock-centrifugal grinder. Main work is performed by flat impact elements located on the rotor, which serve to accelerate crushed particles with subsequent impact of them on the bump elements. An important step in the design of new constructions of shock-centrifugal grinders is to determine size and location of the impact elements on the rotor, without which the grinding process is not possible. In the calculation method presented, the dependencies for determining the velocities and angles of a single particle flight from the surface of a flat impact element for its specified dimensions are proposed. Two variants of an impact element location on the rotor are considered and analyzed: radial and at an angle in the direction of rotor rotation. As a result of research carried out, it is noted that in the case of inclined position of an impact element on the rotor an increase in flight speed and flight angles change in crushed particles, which gives the opportunity to have a positive effect on grinding process.

scholarly journals Comprehensive assessment of the influence of structural friction in a vehicle suspension on its performance

2021 ◽  
Vol 3 (1 (111)) ◽  
pp. 29-36
Author(s):  
Valeriy Pisarev
Keyword(s):  
Decision Making ◽  
Comparative Analysis ◽  
Theoretical Study ◽  
Comprehensive Assessment ◽  
Design Stage ◽  
Vehicle Suspension ◽  
Support Surface ◽  
Friction Coefficients ◽  
The Impact ◽  
Positive Effect

Decision-making regarding the application of any new structure at the design stage requires in practice that it should be compared with the existing one by many indicators. A special feature of the new design of hydropneumatic suspension is the existence of movable connections (screw and splined) as parts of the hydropneumatic element. The presence of structural friction in movable connections requires, in particular, an assessment of the impact of this friction on the process of oscillations when moving through crossed terrain based on comparative analysis. The comprehensive estimate chosen for comparison includes operational properties in terms of ergonomics (smooth movement) and adhesion to the support surface (effort in the contact of wheels with the support surface). The results of a theoretical study involving a vehicle with parameters (weight, dimensions) close to armored personnel carriers BTR70, BTR80, but with hydropneumatic suspensions, demonstrated that when driving on crossed terrain with speeds up to 65 km/h there is a significant reserve in terms of ergonomics. Regardless of the presence (absence) of structural friction, at friction coefficients of up to 0.085. When moving on the surface with large irregularities, the reserve for the maximum allowable (3 g) acceleration in a driver seat is 4.708 times (there is no structural friction) and 3.768 times (structural friction is present). When moving on the surface with small irregularities, the reserve for the maximum permissible (0.5 g) acceleration in a driver seat is 2.093 times (there is no structural friction) and 2.616 times (structural friction is present). Under the most dangerous modes of movement (at the highest speeds) when driving over small irregularities, the presence of structural friction has a positive effect both in terms of ergonomics and stability. Thus, when driving at a speed of 65.679 km/h, the minimum clutch margin is 1.4 times greater, and the acceleration is 1.249 times smaller

Impact of Digitalization on Service Work in Knowledge-Intensive Business Services: An Empirical Study in Tax Consultancies

2019 ◽  
Vol 3 (4) ◽  
pp. 209-222
Author(s):  
Philipp K. Görs ◽  
Henning Hummert ◽  
Anne Traum ◽  
Friedemann W. Nerdinger
Keyword(s):  
Work Engagement ◽  
Service Work ◽  
Psychological Consequences ◽  
Business Services ◽  
Knowledge Intensive Business Services ◽  
Positive Effects ◽  
Knowledge Intensive ◽  
The Impact ◽  
Positive Effect ◽  
Special Case

Digitalization is a megatrend, but there is relatively little knowledge about its consequences for service work in general and specifically in knowledge-intensive business services (KIBS). We studied the impact of digitalization on psychological consequences for employees in tax consultancies as a special case of KIBS. We compare two tax consulting jobs with very different job demands, those of tax consultants (TCs) and assistant tax consultants (ATCs). The results show that the extent of digitalization at the workplace level for ATCs correlates significantly positively with their job satisfaction. For TCs, the same variable correlates positively with their work engagement. These positive effects of digitalization are mediated in the case of ATCs by the impact on important job characteristics. In the case of TCs, which already have very good working conditions, the impact is mediated by the positive effect on self-efficacy. Theoretical and practical consequences of these results are discussed.

Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Infiltration ◽  
Cone Penetration ◽  
Initial State ◽  
Soil Water Infiltration ◽  
Good Improvement ◽  
The Impact ◽  
Positive Effect ◽  
Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

PROGRESS OF RESEARCH IN NUTRITIONAL THERAPY FOR NEW CORONAVIRUS INFECTION (NARRATIVE REVIEW)

2020 ◽  
Vol 7 (11) ◽  
pp. 7-19
Keyword(s):  
Theoretical Study ◽  
Animal Experiments ◽  
Nutrient Status ◽  
Nutritional Therapy ◽  
Review Of The Literature ◽  
Global Concern ◽  
Coronavirus Infection ◽  
Spread Of Infection ◽  
Development Methods ◽  
Positive Effect

Objective: In this review, we highlight the importance of an optimal nutrient status to strengthen the immune system during the COVID-19 crisis, focusing on the most relevant constituents that reduce inflammation and Provide a holistic perspective nutritional therapy the new coronavirus (covid-19) to assist researchers and improving areas for future response plans to deal with these diseases, and to provide a summary of the nutrients that help stop their development. Methods: This is a theoretical study conducted through a comprehensive review of the literature and research in the research engines (PubMed), (Read) and (ELSEVIER) and other new studies published in Chinese; we obtained information nutritional treatment who contributed to increasing the immunity of patients, due to the lack of treatment for this disease. Results: Until now no effective drug for the treatment of new coronavirus, pneumonia (covid-19) has been found. The development of vaccines is still in animal experiments. Recommendations and measures to control the spread of infection and nutritional therapy are still the only way to prevent the spread of covid-19 virus. Because, People relied only on treatments that were effective on previous viruses, for example those that have been used during the SARS and MERS epidemics. Discussion: The Covid-19 virus remains a global concern and more research is needed to control it. In addition, people need to know the nutrition ingredients that have a positive effect on increasing the immunity of the human body.

The Impact of Coping Strategies on Situational Coping in Daily Life: An Ecological Momentary Assessment Study with the mHealth application TrackYourStress (Preprint)

2020 ◽  
Author(s):  
Teresa O'Rourke ◽  
Carsten Vogel ◽  
Dennis John ◽  
Rüdiger Pryss ◽  
Johannes Schobel ◽  
...  
Keyword(s):  
Social Support ◽  
Coping Strategies ◽  
Daily Life ◽  
Stress Coping ◽  
Positive Thinking ◽  
Active Stress ◽  
Situational Coping ◽  
Ecological Momentary ◽  
The Impact ◽  
Positive Effect

BACKGROUND It is necessary to cope with situations in daily life to prevent stress-related health consequences. However, coping strategies might differ in their impact on dealing with stressful situations in daily life. Moreover, the effect of coping strategies on situational coping might differ between women and men. OBJECTIVE The aim of this study was to investigate the impact of coping strategies on situational coping in everyday life situations and to investigate gender differences. METHODS An ecological momentary assessment study with the mobile health app TrackYourStress (TYS) was conducted with 113 participants. Coping strategies were measured at baseline with the coping scales Positive Thinking, Active Stress Coping, Social Support, Support in Faith, and Alcohol and Cigarette Consumption of the Stress and Coping Inventory (SCI). Situational coping was assessed by the question “How well can you cope with your momentary stress-level” (slider 0-100) in daily life over four weeks. Multilevel models were conducted to test the effects of the coping strategies on situational coping. Additionally, gender differences were evaluated. RESULTS Positive Thinking (P=.03) and Active Stress Coping (P=.04) had significant positive impacts on situational coping in the total sample. For women, only Social Support had a significant positive effect on situational coping (P=.046). For men, only Active Stress Coping had a significant positive effect on situational coping (P=.001). Women had higher scores on the SCI scale Social Support than men (P=.007). CONCLUSIONS These results suggest that different coping strategies could be more effective in daily life for women than for men, which should be considered in the development of interventions aimed at reducing stress consequences through coping. Interventions taking gender into consideration might lead to better coping-outcomes than generalized interventions.

THE IMPACT OF WORLD WAR II ON COST ACCOUNTING AT THE SPERRY CORPORATION

2003 ◽  
Vol 30 (2) ◽  
pp. 67-104 ◽  
Author(s):  
Richard K. Fleischman ◽  
R. Penny Marquette
Keyword(s):  
World War Ii ◽  
Performance Management ◽  
Scientific Management ◽  
World War ◽  
Military Contractors ◽  
Management Techniques ◽  
Cost Awareness ◽  
The Impact ◽  
Positive Effect ◽  
The U.S

The impact of World War II on cost accountancy in the U.S. may be viewed as a double-edged sword. Its most positive effect was engendering greater cost awareness, particularly among companies that served as military contractors and, thus, had to make full representation to contracting agencies for reimbursement. On the negative side, the dislocations of war, especially shortages in the factors of production and capacity constraints, meant that such “scientific management” techniques as existed (standard costing, time-study, specific detailing of task routines) fell by the wayside. This paper utilizes the archive of the Sperry Corporation, a leading governmental contractor, to chart the firm's accounting during World War II. It is concluded that any techniques that had developed from Taylorite principles were suspended, while methods similar to contemporary performance management, such as subcontracting, emphasis on the design phase of products, and substantial expenditure on research and development, flourished.

scholarly journals Modulation of Gut Microbiota and Oxidative Status by β-Carotene in Late Pregnant Sows

2020 ◽  
Vol 7 ◽  
Author(s):  
Xupeng Yuan ◽  
Jiahao Yan ◽  
Ruizhi Hu ◽  
Yanli Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Fecal Microbiota ◽  
Control Group ◽  
Metabolic Activities ◽  
The Impact ◽  
Positive Effect ◽  
Β Carotene

Recent evidences suggest that gut microbiota plays an important role in regulating physiological and metabolic activities of pregnant sows, and β-carotene has a potentially positive effect on reproduction, but the impact of β-carotene on gut microbiota in pregnant sows remains unknown. This study aimed to explore the effect and mechanisms of β-carotene on the reproductive performance of sows from the aspect of gut microbiota. A total of 48 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into three groups (n = 16) and fed with a basal diet or a diet containing 30 or 90 mg/kg of β-carotene from day 90 of gestation until parturition. Dietary supplementation of 30 or 90 mg/kg β-carotene increased the number of live birth to 11.82 ± 1.54 and 12.29 ± 2.09, respectively, while the control group was 11.00 ± 1.41 (P = 0.201). Moreover, β-carotene increased significantly the serum nitric oxide (NO) level and glutathione peroxidase (GSH-Px) activity (P < 0.05). Characterization of fecal microbiota revealed that 90 mg/kg β-carotene increased the diversity of the gut flora (P < 0.05). In particular, β-carotene decreased the relative abundance of Firmicutes including Lachnospiraceae AC2044 group, Lachnospiraceae NK4B4 group and Ruminococcaceae UCG-008, but enriched Proteobacteria including Bilophila and Sutterella, and Actinobacteria including Corynebacterium and Corynebacterium 1 which are related to NO synthesis. These data demonstrated that dietary supplementation of β-carotene may increase antioxidant enzyme activity and NO, an important vasodilator to promote the neonatal blood circulation, through regulating gut microbiota in sows.

scholarly journals Tanning Wastewater Treatment by Ultrafiltration: Process Efficiency and Fouling Behavior

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 461
Author(s):  
Fu Yang ◽  
Zhengkun Huang ◽  
Jun Huang ◽  
Chongde Wu ◽  
Rongqing Zhou ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Shear Rate ◽  
Membrane Surface ◽  
Filtration Efficiency ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Transmembrane Pressure ◽  
Leather Industry ◽  
Pore Blocking ◽  
The Impact

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

scholarly journals The Impact of B Corp Certification on Growth

2021 ◽  
Vol 13 (13) ◽  
pp. 7191
Author(s):  
Valerie Paelman ◽  
Philippe Van Cauwenberge ◽  
Heidi Vander Bauwhede
Keyword(s):  
Regression Analysis ◽  
Propensity Score ◽  
Panel Regression ◽  
Medium Term ◽  
Difference In Differences ◽  
Dual Purpose ◽  
Full Effect ◽  
The Impact ◽  
Positive Effect ◽  
Over Time

We empirically test whether B Corp certification affects the short- and medium-term growth rates of sustainable enterprises. These businesses are growing in popularity and prevalence but, due to their hybrid nature, often suffer from external credibility issues and competing internal logics. Because of the rigorous and time-involving audit procedure, B Corp certification potentially sends a credible signal about the sustainable nature of the enterprise to its stakeholders. In addition, the B Corp label could help to straighten out internal tensions and align the company towards its dual purpose. Hence, B Corp certification could contribute to company success. We observe 129 firms that were certified between 2013 and 2018 over a period between six years prior and five years post-certification. Using propensity score matching, we identify 129 non-certified matching companies. On this sample, we conduct a difference-in-differences panel regression analysis to investigate the effect of certification. Our dataset allows us to study how the effects of B Corp certification evolve over time, which was previously untested. Our study documents a positive effect of B Corp certification on turnover growth and also that this effect increases with the time since certification, implying that certification requires some time for its full effect to become apparent.

scholarly journals The impact of regular sperm donation on bulls’ seminal plasma hormonal profile and phantom response

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alicja Kowalczyk ◽  
Elżbieta Gałęska ◽  
Ewa Czerniawska-Piątkowska ◽  
Anna Szul ◽  
Leszek Hebda
Keyword(s):  
Seminal Plasma ◽  
Sperm Donation ◽  
Hormonal Profile ◽  
Holstein Friesian ◽  
Different Seasons ◽  
Day Of The Week ◽  
The Impact ◽  
The Relationship ◽  
Positive Effect

AbstractThe aim of this study was to analyze the relationship between the concentration of hormones in the seminal plasma, the bull maintenance system in the insemination station, and the regularity of sperm donation and the response to the phantom (libido level). An additional goal was to determine whether there is a relationship between the hormonal profile in the blood, the sperm plasma, the oxidative and antioxidant profile in the blood of bulls and the biometry of their testicles and scrotum, as well as the quality of their sperm in both different seasons and intensities of reproductive use. For the study, 220 healthy and sexually mature Polish Holstein–Friesian bulls were used. They all had normal libido and were fed equally. The animals were grouped according to the scheme: young (16–20 month/n = 60) and old (26–30 month/n = 60) including: individually housed (n = 30) and group housed (n = 30) young, old individually housed (n = 30) and group housed (n = 30) (n total animals = 120); young animals donating semen once a week (every Thursday) (n = 25) and sporadically (once every two months on a random day of the week) (n = 25), old animals donating semen once a week (every Thursday) (n = 25 ) and sporadic donors (once every two months on a random day of the week) (n = 25) (n total animals = 100). When analyzing the results of this study, it should be stated that regular use has a positive effect on the secretion of sex hormones in bulls. Higher levels of testosterone and lower levels of estradiol and prostaglandins resulted in higher sexual performance, expressed by a stronger response to the phantom. The differences in favor of regular use were independent of the bull's age. The results of our research illustrate that the quality of semen and its freezing potential may depend on the season and frequency of its collection, as well as on the age of the males.

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