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Advances in Image and Video Processing
Number of Followers: 24  Open Access journalISSN (Print) 2054-7412 Published by Society for Science and Education  [4 journals]
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- Flowstress and Overstress Approaches to Dynamic Viscoplasticity
Authors: Y. Partom
Abstract: Viscoplasticity is mostly modelled by the flowstress approach, where the flowstress (Y) is a function of pressure, temperature, plastic strain and strain rate Y (P, T, ). For dynamic viscoelasticity the flowstress approach is used in hydrocodes together with the radial return algorithm, to determine deviatoric stress components in each computational cell and for each time step. The flowstress approach assumes that during plastic loading, the flowstress in stress space follows the current stress point (current Y). Unloading of a computational cell is therefore always elastic. The overstress approach to dynamic viscoplasticity was used in various versions in the 1950s and early 1960s, before the advent of hydrocodes. By the overstress approach a state point may move out of the quasistatic flow surface upon loading, and hence the term overstress. When this happens, the state point tends to fall back (or relax) onto the quasistatic flow surface through plastic flow, and the rate of this relaxation is an increasing function of the amount of overstress. In this paper we first outline in detail how these two approaches to dynamic viscoplasticity work, and then show an example for which the overstress approach has an advantage over the flowstress approach. The example has to do with elastic precursor decay in planar impact, and with the phenomenon of anomalous thermal strengthening, revealed recently in planar impact tests. The overstress approach has an advantage whenever plastic flow during unloading is of importance.
PubDate: Fri, 17 Mar 2023 00:00:00 +000
- Exploring the Efficacy and Feasibility of Wind Energy as A Panacea for
Eskom’s Sustainable Generation with Energy Security and Energy Poverty
Authors: Dr. Victor Chipane Maleka; Dr. Mohammad Shahidul Islam
Abstract: There is ample proof that South Africa's ongoing reliance on fossil fuels as its primary source of energy consumption. It has contributed to the release of greenhouse gases that have exacerbated ecosystem disruption causing global warming and climate change. The study investigated and evaluated the effectiveness and feasibility of wind energy as a magic bullet to improve energy security, sustainable energy production, and alleviate energy poverty in South Africa. This is in order to improve sustainable energy generation, energy security, and the elimination of these problems. A thorough literature review of papers published between 2015 and 2022 was done in this study. SWOT analysis method (strengths, weaknesses, opportunities, and threats) is also used in the study. According to the analysis, Eskom's deployment of wind energy at a large scale can enhance South Africa's energy security and sustainably provide power while also lowering the country's present level of energy poverty. The systematic literature review indicates that South Africa, particularly in the Eastern and Western Cape regions, offers significant potential for and capacity for renewable wind energy. In order to incorporate renewable sources into its energy mix and achieve energy sustainability, Eskom should use macro-level strategies that discourage carbon-based energy.
PubDate: Fri, 17 Mar 2023 00:00:00 +000
- Micronutrient Mineral and Nutrient Content of Volcanic Soils and Creeks
from the Montserrat Soufriere Hills Volcano. Nature’s Fertilizer:
Mineral Nutrient Content of Volcanic Soils
Authors: Orien L Tulp; Frantz Sainvil, Rolando Branly, Andrew Sciranka, Roberto Guibert, George P Einstein
Abstract: Agricultural soils and potable water supplies provide a major source of minerals known to be essential for plant and animal health. After several hundred years of relative quiescence, the Soufriere Hills Volcano of Montserrat roared back to life in 1995 through 1997, wreaking severe havoc and severe damage to the geography and ecosystems and serious immediate and chronic health risks to the remaining inhabitants of the Island. The pyroclastic ash flow reached temperatures of 1500 °F and progressed down the hillsides at speeds of 80 mph, causing incineration and virtual destruction of everything in its path, while the gaseous and particulate laden plume reached altitudes of 7 miles (10.7 km), impacting air quality and aircraft navigation in the region. A total of 19 individuals became entrapped in the lava flow, and perished quickly as a direct result of the volcanic eruption. Volcanic soils derive from deeper layers of the earths surfaces and are notoriously rich in mineral nutrients representative of those deep mineral deposits. While virtually all combustible objects in the path of the raging ash flow become incinerated within minutes, the aftermath of the eruptions delivers the mineral rich constituents over a wide swath of the surrounding geography often reaching miles from the volcanic origin. Soils and consumable water sources are well known to provide a reliable community source of essential minerals in human nutrition, and in their chronic absence, numerous pathologic sequela may develop. To determine the mineral content of surrounding surface soils, samples of surface ash layers and nearby creeks were obtained from 7 regions and 3 free-flowing creeks and subjected mineral analysis. The surface ash specimens contained abundant amounts of the nutrients Iron, Calcium, Sodium, Magnesium, Sulfur, and non-nutrient Aluminum, intermediate amounts of potassium, Phosphorous, and Manganese, and small amounts of Boron, Copper and Zinc. Creek water runoff originating from higher elevations was consistently acidic with a healthy mean pH of 5.1, and contained smaller proportions of the same minerals, reflective of their relative effective solubility in the acidic water. Thus, the volcanic ash flow while devastating to the environment and public health in the immediate aftermath, provided numerous minerals important to plant and animal nutrition and to human health and health water sources which contributed to the longer-term reinstitution of edible plants and to the recovery of the vibrant lush greenery of the Emerald Isle of the Caribbean.
PubDate: Fri, 17 Mar 2023 00:00:00 +000
- Market Opportunities and New Sheep Meat Products Produced by Sustainable
Farming System
Authors: Sandra Rodrigues; Alfredo Teixeira, Paula Cabo, José Castro, Marina Castro
Abstract: Within the scope of the Open preserve project in northern Portugal, an integrated assessment has been developed to evaluate the efficiency of pyric herbivory to maintain open landscapes and the farm products' quality of livestock products using it. As a measurement of farm system evaluation, some meat products quality was analysed, particularly meat lamb and some meat processed products as hamburgers, sausages, pâtés, and cured legs from carcasses that come out of PGI or PDO quality brands. Results indicated that lambs produced were in the quality requirements of similar products produced in the region. The processed products would be an interesting alternative for the meat industry and a novelty for consumers, adding value to carcasses with low commercial price and consumer reduced acceptability
PubDate: Thu, 16 Mar 2023 00:00:00 +000
- The Effect of Continuous Grazing and Rest Rotational Management Systems on
Grass Species Composition, Basal Cover and Production on Three Soil Types
in the North West Province, South Africa
Authors: Franci Petra Jordaan; Yvette Brits, Jaco Nicolaas van Rooyen
Abstract: Rangelands represent the most extensive land cover type on Earth and many people depend on these rangelands for their livelihoods and for the ecosystem services that effect human wellbeing. The impact of grazing on community structure and ecosystem functioning is a key issue for rangeland management in order to maximize livestock production and sustainability of the operations. It is a known fact that soil differences cause differences in the palatability and utilization of grasses. Year-round continuous grazing is the management strategy used in the communal areas of the North West Province of South Africa. In this study the effect of continuous grazing and rest rotation grazing on grass species composition, basal cover and biomass production on different soil types were assessed. From the results it was clear that the effect of continuous grazing was the biggest on the andesitic soils (high clay), then the diabase soils (medium clay), whilst the effect on the quartzite soils was limited to even positive. In the rest rotation system, the effect of soil type on the different variables was negligibly small and the rangeland remained healthy and productive.
PubDate: Thu, 16 Mar 2023 00:00:00 +000
- Armed Groups and the Environment in Cameroon: The Impact of Boko-Haram and
Anglophone Secessionist on the Environment in Crisis Regions
Authors: Stanley Chung Dinsi
Abstract: Cameroon is blessed with a rich natural environment composed of the forest, rich and diversified biodiversity, soils rich in oil, gas and minerals, beautiful coasts and rivers. Since 2013, Cameroons’ environment has come under serious threats from the activities of Boko-Haram and Anglophone secessionist armed groups. This article assesses the impact of Boko-haram and the Anglophone secessionists on Cameroon’s environment including; the forest, animal and plant biodiversity, rivers, and the soil in crisis areas of the North, North West and South West regions respectively. But, how do non-state armed groups impact the environment and what are the perspectives for strengthening environmental protection' The study uses public policy and constructivism models to analyze legal and policy data on environmental protection and the environmental damages of Boko-Haram and Anglophone secessionists in the North, North West and South West regions of Cameroon respectively. Results of this study show that Bako-Haram and the Anglophone secessionist armed groups are a major cause of destruction of the forest and soil, water pollution and illegal exploitation of biodiversity in violation of international conventions and national conservation laws and policies. This study identifies concerted action of key stakeholders including; international organizations, the state of Cameroon, civil society actors and traditional authorities as a measure to orientate and strengthen environmental protection in Cameroon in crisis zones.
PubDate: Thu, 16 Mar 2023 00:00:00 +000
- A Constrained South African Electricity Supply Chain - What Next'
Authors: Kenneth Mathu
Abstract: Background: The South Africa’s reliance on fossil-fuels for electricity generation for nearly a century, has transformed the nation into a carbon economy, with a heavy carbon footprint, as over 80% of electricity generation and 40% of fossil-fuel production are from coal. The under-serviced aged coal-fired stations, hitherto fail to meet the generation capacity that has contributed power cuts for over a decade. This study explored the constraints of electricity supply chain that culminated into power outages since 2008 covering the aged coal-fired power stations and independent power producers (IPPs) that produces renewable sources of energy. Method: Qualitative research methodology and constructivism research paradigm were pursued, and theories of competitive advantage and sustainable development underpinned the study. The non-probability sampling process was used and interviews were recorded and transcribed. The emanating data was interpreted, coded and analysed via content analysis. Results: The results indicated urgent need for hiring maintenance expertise for the aged coal-fired power stations to minimise loadshedding, while also expediting renewable sources of energy development for the sustainability of electricity supply chain. Conclusion: The outcome of the study would align with the country’s chosen path of “Just Energy Transition” strategy, which embraces clean energy development from renewable sources.
PubDate: Sat, 11 Mar 2023 00:00:00 +000
- The Measured Effects of Barbell Loading in a Flexed vs Neutral Lumbar
Spinal Position: A Case Study
Authors: Brogan Williams; Aaron Horschig, Andrew Lock, Stephen Redmon
Abstract: This case study looks at the physical and psychosocial effects of the lumbar spine under high loads in a macro-flexion (65°) and relative-neutral (29°) position during an isometric 45° hip hinge for up to 25 seconds. A 150kg/330lb weighted barbell used by a powerlifter was taken through 1 set of macro-flexion and relative-neutral. Tightness, discomfort, and pain, as well as when the pain reached a 7/10 VAS were measured. The examiner documented a time stamp for each symptom once verbalized by the participant. For set 1, symptoms became present at 2 seconds (tightness), 5 seconds (discomfort), and 14 seconds (pain) with the set ending at 21 seconds due to 7/10 pain and extreme discomfort reported. There was then a 10-minute pause for the participant to recover and prepare for the next lift. For set 2, only one symptom became present at 20 seconds (tightness), with no discomfort and no pain. This study demonstrates that loaded flexion has the potential to provoke lumbar tissues at a greater rate than a loaded neutral position.
PubDate: Sat, 11 Mar 2023 00:00:00 +000
- Factors Contributing to the Social Exclusion of Secondary School Aged
Youth
Authors: Mari Salminen-Tuomaala; Kaija Nissinen, Ari Haasio
Abstract: The study describes secondary school nurses’, subject teachers’, special needs teachers’, study counsellors’ and school social workers’ (n=60) experiences of factors that contribute to the development of social exclusion in adolescents. The data were collected in Finland using an online survey tool in 2022 and analysed using inductive content analysis. Some factors associated with social exclusion of the adolescents concerned the youth themselves: problems with self-esteem, learning, emotional intelligence, mental health and intoxicants; while other factors concerned families: problems with family dynamics, interaction, mental health and socioeconomic issues. Inadequate support and mental health services were also mentioned by the participants. Mental health problems, especially depression, are relatively common in families and a major risk factor for the development of social exclusion. In addition, some of the other factors, for example problems in family dynamics, could be secondary, reflecting diagnosed or undiagnosed mental health problems. The risk of social exclusion is likely to increase if several of these factors are accumulated in a young person’s life, possibly passed on from the earlier generation and reinforced in the family home.
PubDate: Sat, 11 Mar 2023 00:00:00 +000
- An Appraisal of Plants Used as Health Foods in Mozambique
Authors: Assane, R. S. S; Bell, V, Cuinica, L. G, Chabite, I. T, Fernandes, T. H.
Abstract: A third of Mozambique is considered conservational area and is extremely rich in animal, plant, and marine biodiversity ecosystems. Over 90% of the 33 million population still depends on traditional medicine to meet its primary healthcare needs. While diagnosis has been based on symptoms for lack of laboratories and healthcare staff, respiratory diseases have been rising and with the pandemics the prevalence and assistance to these disorders has increased. Readily available natural plants have been used for many decades as valuable agents due to their content in unknown and also well described phytochemicals. This short but concise research project aimed at supplying an overview of the currently known efficacy of some plant species used traditionally in the north of Mozambique specifically for respiratory diseases. Several secondary metabolites were investigated in some commonly used medicinal plants. This primary work on phytochemical profiling will be useful for future pharmacological, molecular, toxicological, and pre-clinical assessments, contributing to public health pursuits and for guiding future investigations. An oral questionnaire in local language, included questions about the popular name of the plant, therapeutic indication, part used, form of preparation, route of administration, dosage/ingredients, duration of treatment, and adverse effects. Pre-treatment, extract collection, and qualitative phytochemical analysis were investigated on 5 main selected plant species. The most cited species used were Ficus religiosa L, Olax dissitiflora Oliv, Eucalyptus globulus Phil., Catunaregam spinosa (Thunb.) Tirveng, and Eulychnia acida Phil. which revealed several secondary metabolite classes such as alkaloids, flavonoids, tannins, and saponins, with a general absence of coumarins. Plant remedies were prepared mainly as infusion, decoction and maceration, and the ways of administration were oral, inhalation and bath. The most commonly used parts in the treatment were the roots and leaves, with the bark and stem least used.
PubDate: Sat, 11 Mar 2023 00:00:00 +000
- Why is the Incorrect Version of the Special Theory of Relativity Still
Being Studied in Physics Textbooks, Despite all its Experimental
Refutations
Authors: Antonov Alexander Alexandrovich
Abstract: The article states that the existing version of the special theory of relativity (STR) is incorrect, since relativistic formulas obtained therein are incorrect; they have been incorrectly explained by using the incorrect principle of speed of light non-exceedance and entailed wrong conclusions about physical unreality of imaginary numbers and existence of only our visible universe. It mentions experimental evidence of the foregoing, obtained by the author within study of transient and resonant processes in linear electric circuits. It is shown that the existing version of the STR implies conclusions on nonexistence of tsunami and bell ringing, piano music and swinging children’s swings, as well as many other real processes. It is also shown that the existing version of the STR denies even the possibility of existence of radio- and electrical engineering. Therefore, it is concluded that existing university physics textbooks should be corrected.
PubDate: Sat, 11 Mar 2023 00:00:00 +000
