Determination of the point of zero charge of alumina by batch equilibration method

In this work we present the points of zero charge, pHpzc, of five commercial alumina samples, of an alumina/solution ratio of 0.100g/25 ml, obtained by batch equilibration method. As an inert electrolyte, KNO3 of 0.001 - 0.1 moldm-3 concentration was used. The obtained points of zero charge values are about 7 and they are independent of KNO3 concentration, except the sample labeled as ICN (Alumina B). In this case, the increase in electrolyte concentration (from 0.001 to 0.1 moldm-3) leads to a decrease in pHpzc (from 7.5 to 6.7) indicating specific sorption of K+ ions on the sample.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

A milestone in the era of esports: The Olympics through the lens of virtual reality

Whether the International Olympic Committee (IOC) ever includes electronic sports (esports) in the official program of the Olympic Games, the popularity of competitive gaming continues to grow—sports present a modern audience powerhouse the world cannot fail to notice. By the end of 2025, the number of viewers in esports is expected to reach 640.8 million and revenue growth of 1,866.2 billion U.S. dollars (Gough, 2022). Over 170 colleges in the United States have established varsity esports teams and offer esports players' educational opportunities, including partial or full scholarships (Lyman, 2022). Esports has also found its place in schools, largely influencing the youth (Rothwell and Shaffer, 2019). Additionally, numerous NBA teams have entered the esports race, and even Usain Bolt owns an esports team (Gardner, 2022), perhaps better illustrating esports' global prevalence. In 2021, the IOC took a step closer to the digital world, creating the Olympic Virtual Series (OVS). The main objective was to promote the development of virtual sports games and engage with the gaming communities worldwide. The OVS consisted of five different games: baseball (Powerful Pro Baseball 2020), cycling (Zwift), rowing (World rowing, using a rowing machine), sailing (Virtual Regatta), and motor racing (Gran Turismo). The IOC fused traditional elements of sport physicality and video games to uniquely incorporate physical activity (PA) to new audiences, connecting “e” and sports through the Olympic Movement (Palaar, 2021). Opposingly, the 2022 Asian Games (postponed to 2023 due to COVID-19) in Hangzhou will be the first official continental competition to include eight esports games played on computers, consoles, and even smartphone devices (Daniels, 2021). While these actions by the IOC certainly took cognizance of esports and presented it to a world audience, none of the included games utilized virtual reality (VR) technology. Compared to the vast library of traditional esports games (e.g., Dota 2, League of Legends, Apex, CS:GO), VR games have a small selection of titles—which has affected the global VR prevalence in the gaming world. However, an excellent example is the VR game Onward, which (according to players) brought new features and a higher skill ceiling than traditional games, in addition to the physical embodiment and “immersiveness” for players (Turkay et al., 2021). VR is defined as an immersive and multisensory experience for the user, with the support of multimedia components such as VR headset and body tracking sensors (Gigante, 1993). As opposed to the 360° VR, which relies on the video recorded by the actual camera and then implemented into the system—this gives users a more realistic view and experience. However, both rely on the physical headset device with or without motion controllers. VR and the gaming industry joint became more evident as VR became a globally more available technology (e.g., Oculus Rift, HTC Vive, PlayStation) on the market. While the VR player base is not as big as Dota 2 or CS:GO, VR esports have a promising future with exponential growth, forecasted to reach 2.4 billion U.S dollars by 2024 (Clement, 2022). Besides games, VR technology has wide application in the rehabilitation of specific populations, psychology, psychiatry, education, and even sports performance (Lange et al., 2010; Salem and Elokda, 2014; Izard et al., 2018; Michalski et al., 2019; Park et al., 2019; Kaplan et al., 2021; Lee et al., 2021)

Cretaceous-Paleogene boundary (KPB) Fish Clay at Højerup (Stevns Klint, Denmark): Ni, Co, and Zn of the black marl

The black marl of the Fish Clay at Højerup is mainly made up of biogenic calcite and cheto-Mg-smectite. We suggest that the formation of the smectite occurred during the latest Maastrichtian (or earlier) and that it represents a short period of rapid redeposition through coastal erosion occurring at the Cretaceous-Paleogene boundary (KPB) sea level lowstand. The smectite of the black marl shows enhanced concentrations of Ni, Co, and Zn. The predominant source of these metals was probably the impact-ejecta fallout deposited on the top of nearby soil which was leached by the impact-induced-acidic surface waters. Most of the content of Ni and Co in the smectite is derived from the chondritic component of the fallout, but the ultimate origin of Zn may have been the impact-target rocks. Incorporation of the metals into the smectite took place during the KPB but before its redeposition at the Fish Clay site. The biogenic calcite-rich fraction of the black marl also shows high concentrations of Ni, Co, and Zn. The ultimate source of the metals was also probably the impact-ejecta fallout on the nearby soil at Stevns Klint. Enrichments of Ni in the biogenic calcite-rich/smectite fractions of the black marl represent the sudden input of the metal into the seawater at the KPB

Environmental and macroeconomic impact assessment of different development scenarios to organic and low-input farming in Croatia

This study was commissioned by the UN Food and Agriculture Organization (FAO) within the framework of an FAO technical assistance project for Croatia. It assessed macroeconomic and environmental impact assessment of large-scale conversion to organic agriculture. It examined the consequences of such a conversion to national agricultural output and related environmental and economic performance. The assessment also took into account the impact of wide-spread adoption of organic agriculture on farm-upstream linked sectors (FULS). These include energy production and supply, manufacturing of agri-chemical inputs, trade, transport and research, education, advisory, veterinary and administrative services. The agricultural output, environmental and economic performance of the baseline scenario (average of 2001-2003) was compared with fourteen development scenarios involving various shares of utilised agricultural land (UAA) under organic management (10, 25, 50 and 100 per cent) and different yields (100, 75 and 50 per cent of the baseline). In order to obtain the real value added (RVA) created by farming and FULS, the generated gross value added (GVA) was corrected for the associated environmental costs (damage to air, water and soil) and public investments. A monetary value was assigned to all identified environmental damages throughout farming and FULS using various environmental accounting methods. If the entire UAA in Croatia converted to organic farming and if the crops and livestock gave the same yields as in the baseline situation, the farming and FULS would generate a 43 per cent higher annual GVA and 155 per cent higher annual RVA than the baseline scenario. This scenario implies refraining from the use of nearly all agri-chemical inputs. It consumes far less fossil energy (notably in FULS) and causes less environmental damage to soil and water (notably in the farming sector). Consequently, its environmental costs are nearly two times lower than in the baseline. The study results suggest that Croatian farming and FULS in the period 2001-2003 when measured in terms of RVA produced a negative effect on the economy and society in general. Farming is the key sector since it accounts for 90 per cent of the workforce, 61 per cent of GVA, 89 per cent of environmental costs and 77 per cent of public investments of the entire economic chain examined. The scenario involving a 100 per cent organic area, but yielding only 75 per cent of the baseline scenario produces a 17 per cent lower GVA. However, when corrected for public investments and environmental costs it results in 71 per cent higher RVA than the baseline scenario. The 100 per cent organic area scenario achieving only half of the baseline yields results in both lower GVA (75 percent lower) and RVA (6 per cent lower) than the baseline scenario. Of all examined scenarios, this is the least favourable for organic farming as its results exhibit the biggest discrepancies in comparison with the baseline situation. Similar results were obtained in all other scenarios (involving 50, 25 and 10 per cent organic area with 100, 75 and 50 per cent yield levels as compared to the baseline). The organic options, measured against the RVA created are better (7-89 per cent), only in cases where the yield level is 75 or 100 percent of the baseline. If the obtained yields are 50 per cent lower, the organic scenario options create both lower GVA (1, 19 and 37 per cent) and RVA (1, 2 and 3 per cent) than the baseline. The scenarios assuming a 10 per cent premium price (10 and 25 per cent organic area achieving 75 per cent of the baseline yields) create about the same GVA as the baseline, but 10-25 per cent higher RVA. All scenarios involving organic farming decrease environmental costs compared to the baseline. Provided the yield is not 50 per cent lower, all organic scenarios result in a higher RVA than the baseline. The agricultural output (yields) remains the key factor in determining the feasibility of a shift to organic farming. A severe reduction in agricultural output jeopardises national food security. However, since organic farming goes hand in hand with careful management, in the case of Croatia it would not necessarily lead to (much) lower yields. Pioneering efforts in Croatia, as well as evidence from other countries with a similar agricultultural situation also indicate this. Conversion to large-scale organic farming requires high human and social capital. Organic farming is low-input from the point of view of the use of external farming inputs, but is high-input from the point of view of the knowledge and skills needed. In the case of Croatia where farmers and other key stakeholders have a relatively low level of general education and poor agricultural training, this point will certainly be the main obstacle preventing a greater spread of organic farming. Policy efforts should therefore focus primarily on stimulating the formation of social capital and increasing human capacities of all stakeholders involved in the organic food chain

Impact of Organic Agriculture on the Environmental and Economic Performance of Croatia

Within the framework of an FAO technical assistance project for Croatia a study assessing the feasibility of large-scale conversion to organic farming was carried out. It examined the consequences of the conversion of a substantial portion of Croatian agricultural land to organic farming in relation to national agricultural output (food security) and related environmental and economic performance. As farming is closely linked with a range of economic activities, besides farming the assessment also took into account the impact of wide-spread adoption of organic agriculture on farm-upstream linked sectors (FULS). These include energy production and supply, manufacturing of agri-chemical inputs, trade, transport and research, education, advisory, veterinary and administrative services. The agricultural output, environmental and economic performance of the baseline scenario (average of 2001-2003) was compared with fourteen development scenarios involving various shares of utilised agricultural land (UAA) under organic management (10, 25, 50 and 100 per cent) and different yields (100, 75 and 50 per cent of the baseline). In order to enable the same consumer purchasing power as in the baseline situation, organic products were assumed to obtain no premium price in twelve scenarios. In two scenarios approaching the current situation in some European countries (10 and 25 per cent of UAA under organic management with 75 per cent yield) a 10 per cent premium price for organic produce was included. In order to obtain the real value added (RVA) created by farming and FULS, the generated gross value added (GVA) was corrected for the associated environmental costs (damage to air, water and soil) and public investments. The public investments, emissions and environmental degradation of air, water and soil were quantified using data from various official documents and databases, as well as by performing new calculations. A monetary value was assigned to all identified environmental damages throughout farming and FULS using various environmental accounting methods. The difference between the GVA created by the examined economic chain and the sum of environmental costs and public investments resulted in the RVA. The RVA was used as a measurement indicating the economic feasibility of organic farming development scenarios as compared with the baseline scenario. If the entire UAA in Croatia converted to organic farming and if the crops and livestock gave the same yields as in the baseline situation, the farming and FULS would generate a 43 per cent higher annual GVA and 155 per cent higher annual RVA than the baseline scenario. This scenario implies refraining from the use of nearly all agri-chemical inputs. It consumes far less fossil energy (notably in FULS) and causes less environmental damage to soil and water (notably in the farming sector). Consequently, its environmental costs are nearly two times lower than in the baseline. The study results suggest that Croatian farming and FULS in the period 2001-2003 when measured in terms of RVA produced a negative effect on the economy and society in general. Farming is the key sector since it accounts for 90 per cent of the workforce, 61 per cent of GVA, 89 per cent of environmental costs and 77 per cent of public investments of the entire economic chain examined. The scenario involving a 100 per cent organic area, but yielding only 75 per cent of the baseline scenario produces a 17 per cent lower GVA. However, when corrected for public investments and environmental costs it results in 71 per cent higher RVA than the baseline scenario. The 100 per cent organic area scenario achieving only half of the baseline yields results in both lower GVA (75 percent lower) and RVA (6 per cent lower) than the baseline scenario. Of all examined scenarios, this is the least favourable for organic farming as its results exhibit the biggest discrepancies in comparison with the baseline situation. Similar results were obtained in all other scenarios (involving 50, 25 and 10 per cent organic area with 100, 75 and 50 per cent yield levels as compared to the baseline). The organic options, measured against the RVA created are better (7-89 per cent), only in cases where the yield level is 75 or 100 percent of the baseline. If the obtained yields are 50 per cent lower, the organic scenario options create both lower GVA (1, 19 and 37 per cent) and RVA (1, 2 and 3 per cent) than the baseline. The scenarios assuming a 10 per cent premium price (10 and 25 per cent organic area achieving 75 per cent of the baseline yields) create about the same GVA as the baseline, but 10-25 per cent higher RVA. All scenarios involving organic farming decrease environmental costs compared to the baseline. Provided the yield is not 50 per cent lower, all organic scenarios result in a higher RVA than the baseline. The agricultural output (yields) remains the key factor in determining the feasibility of a shift to organic farming. A severe reduction in agricultural output jeopardises national food security. However, since organic farming goes hand in hand with careful management, in the case of Croatia it would not necessarily lead to (much) lower yields. Pioneering efforts in Croatia, as well as evidence from other countries with a similar agricultultural situation also indicate this. Conversion to large-scale organic farming requires high human and social capital. Organic farming is low-input from the point of view of the use of external farming inputs, but is high-input from the point of view of the knowledge and skills needed. In the case of Croatia where farmers and other key stakeholders have a relatively low level of general education and poor agricultural training, this point will certainly be the main obstacle preventing a greater spread of organic farming. Policy efforts should therefore focus primarily on stimulating the formation of social capital and increasing human capacities of all stakeholders involved in the organic food chain

Energy efficiency of residential buildings in Serbia

In this paper, presented is the stale-of-the-art of energy Efficiency of residential buildings in Serbia. Special attention is paid to energy efficiency in already existing buildings. The average energy consumption in residential buildings in Serbia is over 150 kWhm(-2) per year, while in developed European countries it is about 50 kWm(-2) per year. In this paper examined is the contribution of ventilation losses, through the windows of low quality, regardless whether they are poorly made, or made from bad materials, or with no adeguate glass. Besides ventilation losses, which are of major importance in our buildings, special attention is paid to transmission losses, which are conseguence of the quality and energy efficiency of the facade. All of the above statements are proved by measurements obtained on a representative building of the Block 34 in New Belgrade, built in the eighties of the last century. In addition to measurements performed the calculation of energy consumption for heating during winter has been made. The results of two different methods of calculation of energy consumption for heating are compared with the values obtained by measuring

KVALITETA ŽIVOTA PACIJENTICA S OSTEOPOROTIČNIM VERTEBRALNIM PRIJELOMIMA

The aim of this study was to estimate the quality of life in females with primary osteoporosis and vertebral fractures as a consequence of the disease, and to compare it to people without vertebral fractures. Subjects and Methods: Our crosssectional study included 200 female patients with primary osteoporosis (100 with vertebral fractures and 100 without fractures), mean age 63.85±8.52 years, who received treatment at the Clinic for Medical Rehabilitation, Clinical Center of Vojvodina in Novi Sad. Data were based on history, questionnaire, and measurements of bone mineral density by DXA method using the Lunar Prodigy Primo device. Quality of life assessment was done by use of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41). Vertebral deformities were established by lateral radiography of the cervical, thoracic and lumbar regions by an experienced radiologist. Statistically signifi cant differences were established between the two groups, in particular for pain (t=-2.72, p=0.01), daily activities (t=-3.67, p=0.01), performing housework (t=- 4.84, p=0.01), mobility (t=-3.40, p=0.01), leisure activities (t=-2.66, p=0.01) and perception of health status (t=2.48, p=0.05). Results: The results indicated that the quality of life in patients with vertebral fractures did not differ according to the level of fracture compared to the control group. Patients with vertebral fractures had a number of limitations due to pain and poorer physical functioning compared to those without fractures, while the quality of life dependence on the level of fracture was not recorded.Cilj istraživanja bio je procijeniti kvalitetu života žena s primarnom osteoporozom i prisutnim vertebralnim prijelomima kao posljedicom bolesti u odnosu na osobe bez vertebralnih prijeloma. U ispitivanju je sudjelovalo 200 bolesnica s primarnom osteoporozom (100 s vertebralnim prijelomima, 100 bez vertebralnih prijeloma) srednje dobi 63,85±8,52 godina, koje su provele terapiju u Klinici za medicinsku rehabilitaciju Kliničkog centra Vojvodine u Novom Sadu. Podatci su zasnovani na anamnezi, upitnicima, kao i mjerenjima mineralne koštane gustoće metodom DXA pomoću uređaja Lunar Prodigy Primo. Vertebralne frakture su potvrđene rendgenskim slikama cervikalne, torakalne i lumbalne kralježnice očitanim od iskusnog radiologa. Kvaliteta života procijenjena je primjenom upitnika QUALEFFO-41. Dobiveni rezultati ukazali su na statistički značajne razlike između ispitivanih skupina u intenzitetu boli (t=-2,72; p=0,01), svakodnevnim aktivnostima (t=-3,67; p=0,01), obavljanju kućanskih poslova (t=-4,84; p=0,01), pokretljivosti (t=-3,40; p=0,01), društvenim aktivnostima (t=-2,66; p=0,01), percepciji zdravstvenog stanja (t=2,48; p=0,05). Rezultati ukazuju na to da se kvaliteta života u bolesnica s vertebralnim prijelomima ne razlikuje prema razini prijeloma u odnosu na kontrolnu skupinu. Bolesnici s vertebralnim prijelomima imaju brojna ograničenja zbog boli i lošijeg fi zičkog funkcioniranja u odnosu na osobe bez osteoporotičnih prijeloma, dok zavisnost kvalitete života o razini prijeloma nije utvrđena

Structure and immunohistochemistry of the human lenticulostriate arteries

Background: Data about the structure and immunohistochemistry of the lenticulostriatearteries (LSAs), although very important for medical research and clinicalpractice, have been rarely reported in literature.Materials and methods: Fourty serially sectioned LSAs were stained with hematoxilinand eosin, and prepared for immunohistochemistry.Results: Our examination revealed a typical endothelial lining and a narrow subendothelialspace with subintimal smooth muscle cells occasionally. The internalelastic lamina was fragmented or absent in the smallest LSAs branches. The mediacoat, with a mean diameter of 148.5 μm, contained typical smooth muscle cellswhich formed 14.2 layers on average and showed a positive immune reactions foralfa-actin, desmine, laminin and collagen IV. The thin adventitial coat containedfibroblasts, collagen fibers, and nerve bundles, with the strongest immunopositivityto thyrosin hydroxilase. The immune reactions against CD31 and CD34 proteins,endothelial nitric oxide synthase, S 100 protein, neurofilament protein and synaptophysin,seem to be performed in the LSAs wall for the first time. Similarly,the thickness of the LSAs wall and its coats have never been reported, nor thenumber of the smooth muscle cell layers.Conclusions: Our results related to the structure and immunohistochemistry ofthe LSAs could be important in cerebrovascular pathology, neurology and neurosurgery

Expression of p53 protein in Barrett’s adenocarcinoma and adenocarcinoma of the gastric cardia and antrum

Background/Aim. Most studies of esophageal and gastric adenocarcinomas have shown a very high rate of p53 gene mutation and/or protein overexpression, but the influence of the tumor site upon the frequency of p53 protein expression has not been evaluated (gastroesophageal junction, Barret's esophagus, and antrum). The aim of our study was to analyze the correlation between the selected clinico-pthological parameters, and p53 protein overexpression in regards to the particular tumor location. Methods. The material comprised 66 surgical specimens; 10 were Barrett’s carcinomas, 25 adenocarcinomas of the gastric cardia (type II adenocarcinoma of the esophagogastric junction - EGJ), and 31 adenocarcinomas of the antrum. Immunostaining for p53 protein was performed on formalin-fixed, paraffin-embedded tissue sections, using the alkaline phosphatase - antialkaline phosphatase (APAAP) method. The cases were considered positive for p53 if at least 5% of the tumor cells expressed this protein by immunostaining. Results. There was no significant difference observed between the studied groups in regards to age, sex, Lauren’s classification and tumor differentiation. There was, however, a significant difference observed in the depth of tumor invasion between Barrrett’s adenocarcinoma and adenocarcinoma of the cardia compared with the adenocarcinoma of the antrum. Namely, at the time of surgery, both Barrett’s adenocarcinomas and adenocarcinomas of the cardia, were significantly more advanced comparing with the adenocarcinomas of the antrum. Overexpression of p53 was found in 40% (4/10) of Barrett’s adenocarcinomas, 72% (18/25) of adenocarcinoma of the cardia and 65% (20/31) of adenocarcinoma of the antrum. No significant differences in p53 expression in relation to sex, type (Lauren) of tumor, depth of invasion, lymph node involvement, or tumor differentiation were observed in any of the analyzed groups of tumors. Patients with more advanced Barrett’s adenocarcinoma and in the cases of lymph node invasion revealed tendency for the greater p53 positivity compared with the early forms and lymph node-negative cases; however, this difference was not significant according to the statistical analysis. With regard to adenocarcinoma of the cardia, higher rates of p53 positivity were recorded in poorly differentiated, more advanced cases with lymph node invasion. Nevertheless, none of these differences was statistically significant. On the contrary, in the patients with adenocarcinoma of the antrum, greater p53 positivity was revealed in early forms without lymph node involvement, but the observed difference was not statistically significant. Conclusion. No significant differences in p53 protein expression in terms of sex, type (Lauren) of tumor, depth of invasion, lymph node involvement, or tumor differentiation were observed in any of the analyzed groups of tumors (Barrett’s adenocarcinoma, adenocarcinoma of the cardia and adenocarcinoma of the antrum)