The Problems in Delignification of Dry Wood by Kraft Process

2016 ◽  
Vol 688 ◽  
pp. 3-9
Author(s):  
Anton Geffert ◽  
Jarmila Geffertova ◽  
Blazej Seman

The objective of this study was to assess the causes of the problems arising in the CBC kraft cooking of several types of hardwood chips particularly in view of high dry matter but also in view of chip thickness and character of wood.High dry matter of processed chips influences negatively delignification. Similar effect on delignification is achieved by wood character (anatomic and morphological properties of cell elements, chemical composition, portion of heart and sapwood).Chips thickness has the most significant impact on delignification process comparing to other monitored characteristics. The increase of chips thickness by 1-2 mm has significant negative impact on monitored characteristics of kraft cooking – yield, Kappa number and amount of rejects.Displacement CBC kraft procedure is more sensitive on the deviation from standard conditions than conventional kraft cooking.The problems occurring during kraft cooking of different wood chips mixtures with high dry matter by CBC procedure are possible to resolve by technological and organizational precautions – separate chipping and storage of chips of heart and non-heart woods, preparation of thinner chips of heart wood, chips pre-vaporing before kraft cooking.

2020 ◽  
Vol 35 (2) ◽  
pp. 161-171
Author(s):  
Madhuri Pydimalla ◽  
Ramesh Babu Adusumalli

AbstractThe objective of this study was to understand the influence of bleaching on % residual lignin, water retention value, brightness and morphological properties of Subabul heartwood and sapwood pulps. The second aim was to compare the properties of unbleached and bleached handsheets with respect to tensile index and fractography. Screened wood chips of Subabul were subjected to kraft cooking (165 °C, 3 hours) followed by ECF bleaching and refining. When unbleached handsheets were compared, higher tensile index was found for sapwood sheets (29.8 N.m/g) than heartwood sheets (12.8 N.m/g). Therefore, it is recommended to use unbleached sapwood sheets for packaging grade applications. The bleached pulps have exhibited negligible residual lignin (0.1 %), higher water retention value (∼21) and higher brightness (88 %) compared to unbleached pulps. Subsequently, the bleached heartwood sheets revealed higher tensile index (∼7 fold) and higher modulus of elasticity (∼2.7 fold) compared to unbleached heartwood sheets. For printing grade applications bleached sapwood and bleached heartwood pulps are equally recommended, because no differences were observed in their pulp and sheet characteristics.


2012 ◽  
Vol 8 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Zsuzsanna Horváth ◽  
Béla Marosvölgyi ◽  
Christine Idler ◽  
Ralf Pecenka ◽  
Hannes Lenz

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.


2020 ◽  
Author(s):  
Philip Boakye

The acceptance of electronic laboratory information system (LIS) is gradually increasing in developing countries. However, the issue of time effectiveness due to computerization is less clear as there is fewer accessible information. One of the key issues for laboratorians is their indecision with LISs’ would-be effect of time on their work. A polyclinic in Ghana was in the process of implementing electronic LIS. Several of the laboratorians did not have knowledge and skill in computing and there were disagreeing views on the time effectiveness of the LIS after implementation. The management of the polyclinic laboratory was concerned to assess time advantageousness of recording data when using the electronic LIS compared with paper-based LIS. <div><br></div><div>Five randomly selected laboratorians were provided two sheets of paper with tables to document the time they spent for both paper-based and electronic LIS. Data were collected for a total of 230 records,115 electronic LIS and 115 paper-based LIS. The t-test (mean-comparison test) was computed to compare the means of both electronic and paperbased LIS times. </div><div><br></div><div>There was a statistical significant difference in the time spent between electronic and paper-based LIS. The time spent between paper-based and electronic LIS was 0.41 minutes (95% CI 0.15 to 0.66) longer than in electronic LIS. </div><div><br></div><div>LIS can be adopted in polyclinics without having significant negative impact on time spent between electronic and paper-based LIS. More time–motion studies that include laboratorians are however necessary in order to get a more complete picture of time spent between electronic and paper-based LIS. </div>


Author(s):  
Ekaterina Maksimova ◽  
Ekaterina Maksimova ◽  
Vladimir Zhigulsky ◽  
Vladimir Zhigulsky ◽  
Vladimir Shuisky ◽  
...  

The macrophyte thicket ecosystems of higher aquatic vegetation in the Neva Bay (NB) and Eastern Gulf of Finland (EGoF) perform many important roles, including acting as the habitats, nesting sites and migration sites for aquatic and semi-aquatic birds, creating the specific conditions necessary for the spawning and growth of many species of fish, and taking part in the self-purification of the aquatic ecosystems. Many anthropogenic disturbances, hydraulic works in particular, have a significant negative impact on these macrophyte thicket ecosystems. In recent years, the active growth of a new type of macrophyte thicket has been observed in the NB. This is due to the aftereffects of the construction of the Saint Petersburg Flood Prevention Facility Complex (FPFC). It is quite likely that the total macrophyte thicket area in these waters is currently increasing. In the future, it will be necessary to assess the environmental impacts of the hydraulic works on the macrophyte thicket of the NB and EGoF, taking into account the background processes of the spatiotemporal dynamics of the reed beds in the waters in question. To do this, it will be necessary to carry out a comprehensive study of these ecosystems and identify patterns in their spatial and temporal dynamics. The program of the study has been developed and is currently being implemented by Eco-Express-Service, a St. Petersburg eco-design company.


2020 ◽  
Vol 26 (4) ◽  
pp. 397-406
Author(s):  
T. E. Chekanova

The presented study examines the problems of integration of the national banking systems of the member states of the Eurasian Economic Union (EAEU).Aim. The study aims to examine the major differences in various aspects of functioning of banking systems in the EAEU member states in terms of their impact on integration processes.Tasks. The author identifies the most prominent features of the banking systems of the EAEU states; reveals the depth of the existing differences through a comparative analysis of various indicators of national banking systems; outlines ways of overcoming integration problems associated with differences in the banking sectors of the Union states.Methods. This study is based on universal general scientific methods and elements of comparative, functional, and economic analysis within the framework of a systems approach. The author uses regulatory documents and banking reports of the EAEU states, statistical and analytical materials of the Eurasian Economic Commission (EEC), and data of Moody’s international rating agency.Results. The study identifies a number of aspects that contain the major differences in the functioning of banking systems in the EAEU member states; highlights the disproportions in the scale, level of development, financial stability, and risks of the banking spheres of the Union states; comparatively analyzes the proportion of banking and non-banking structures in the system and the share of the government and non-resident companies in the capital of banks; marks the difference in the pricing of banking services; determines differences in the existing approaches to banking regulation and the established standards; analyzes the major differences in the legislative acts of the central banks and governments of the EAEU member states and in the terms and definitions used. According to the results of the study, the major factors hindering the development of integration processes between the banking systems of the EAEU states are identified.Conclusions. The existing differences between the banking systems of the EAEU countries are diverse and multifaceted. The author states that the aspects addressed in this study have a significant negative impact on the further development of integration processes, describing the major directions and actions of the member states aimed at minimizing the exiting differences, which are required to facilitate the convergence of the states and the transition towards a common financial market.


Neurosurgery ◽  
2019 ◽  
Vol 86 (1) ◽  
pp. 132-138
Author(s):  
Christopher D Shank ◽  
Nicholas J Erickson ◽  
David W Miller ◽  
Brittany F Lindsey ◽  
Beverly C Walters

Abstract BACKGROUND Neurosciences intensive care units (NICUs) provide institutional centers for specialized care. Despite a demonstrable reduction in morbidity and mortality, NICUs may experience significant capacity strain with resulting supraoptimal utilization and diseconomies of scale. We present an implementation study in the recognition and management of capacity strain within a large NICU in the United States. Excessive resource demand in an NICU creates significant operational issues. OBJECTIVE To evaluate the efficacy of a Reserved Bed Pilot Program (RBPP), implemented to maximize economies of scale, to reduce transfer declines due to lack of capacity, and to increase transfer volume for the neurosciences service-line. METHODS Key performance indicators (KPIs) were created to evaluate RBPP efficacy with respect to primary (strategic) objectives. Operational KPIs were established to evaluate changes in operational throughput for the neurosciences and other service-lines. For each KPI, pilot-period data were compared to the previous fiscal year. RESULTS RBPP implementation resulted in a significant increase in accepted transfer volume to the neurosciences service-line (P = .02). Transfer declines due to capacity decreased significantly (P = .01). Unit utilization significantly improved across service-line units relative to theoretical optima (P &lt; .03). Care regionalization was achieved through a significant reduction in “off-service” patient placement (P = .01). Negative externalities were minimized, with no significant negative impact in the operational KPIs of other evaluated service-lines (P = .11). CONCLUSION Capacity strain is a significant issue for hospital units. Reducing capacity strain can increase unit efficiency, improve resource utilization, and augment service-line throughput. RBPP implementation resulted in a significant improvement in service-line operations, regional access to care, and resource efficiency, with minimal externalities at the institutional level.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1261
Author(s):  
Aiping Tao ◽  
Qun Liang ◽  
Peng Kuai ◽  
Tao Ding

Based on the panel data of 224 prefecture-level and above cities in China from 2003 to 2016, this paper empirically studies the impact of urban sprawl on air pollution and introduces a mediating effect model to test the mediating role of vehicle ownership concerning the impact of urban sprawl on air pollution. The research in this paper arrives at three conclusions. First, urban sprawl has a significant positive effect on air pollution, and this conclusion is still valid after solving the endogeneity problem and conducting a robustness test. Second, the results of mediating effect test show that urban sprawl indirectly affects air pollution through the partial mediating effect of vehicle ownership. By removing the mediating effect, urban sprawl has a significant negative impact on air pollution, indicating that the mediating effect of vehicle ownership is higher concerning the impact of urban sprawl on air pollution. Third, further panel quantile regression results show that the higher the level of air pollution, the weaker the mediating effect of vehicle ownership and the stronger the direct effect of urban sprawl on air pollution. These conclusions can provide some empirical support for solving the air pollution problems caused by urban sprawl in China.


Author(s):  
Henry Olayere Obanife ◽  
Nasiru Jinjiri Ismail ◽  
Ali Lasseini ◽  
Bello B. Shehu ◽  
Ega J. Otorkpa

Abstract Background Road traffic accident (RTA) is the eighth leading cause of death worldwide. Motorcycle-associated head injury is the leading cause of road traffic associated morbidity and mortality in developing countries. Even though the incidence and mortality of head injury from motor cycle crash is on the increase in developing countries, especially in the African continent, most of the studies published in the literature on this subject matter took place in the developed Western countries. Methods This is a retrospective cross-sectional study of data from patients managed in our institution between December 2014 and November 2016. Results One hundred and eighty-four patients were analyzed. None of the patients used safety helmet for protection. The mean age was 27.6 ± 17.2 years with male female ratio of 6.7:1. Lone crash by cyclists and collisions accounted for 66.8% and 33.1% of the cases, respectively. Passengers and riders comprised 75% of the patients, while 25% were vulnerable pedestrians. The most frequently abused substance by the patients was tramadol (65.52%). Severe head injury and pupillary abnormality were found in 23.9% and 45.5% of the patients, respectively. Cranial CT scan showed abnormalities in 40.2% of the patients. Surgery was done in 28.3% of the patients with mortality rate of 20.7%. Conclusions The use of motorcycle as a mean of transportation has caused significant negative impact on the society. Young people, who constitute the workforce, are majorly affected, and this invariably leads to a serious economic burden on the concerned families and communities.


2020 ◽  
Vol 24 (5) ◽  
Author(s):  
Jinan Liu ◽  
Apostolos Serletis

Abstract We reexamine the effects of the variability of money growth on output, raised by Mascaro and Meltzer (1983), in the era of the increasing use of alternative payments, such as credit cards. Using a bivariate VARMA, GARCH-in-Mean, asymmetric BEKK model, we find that the volatility of the credit card-augmented Divisia M4 monetary aggregate has a statistically significant negative impact on output from 2006:7 to 2019:3. However, there is no effect of the traditional Divisia M4 growth volatility on real economic activity. We conclude that the balance sheet targeting monetary policies after the financial crisis in 2007–2009 should pay more attention on the broad credit card-augmented Divisia M4 aggregate to address economic and financial stability.


Südosteuropa ◽  
2020 ◽  
Vol 68 (4) ◽  
pp. 505-529
Author(s):  
Kujtim Zylfijaj ◽  
Dimitar Nikoloski ◽  
Nadine Tournois

AbstractThe research presented here investigates the impact of the business environment on the formalization of informal firms, using firm-level data for 243 informal firms in Kosovo. The findings indicate that business-environment variables such as limited access to financing, the cost of financing, the unavailability of subsidies, tax rates, and corruption have a significant negative impact on the formalization of informal firms. In addition, firm-level characteristics analysis suggests that the age of the firm also exercises a significant negative impact, whereas sales volume exerts a significant positive impact on the formalization of informal firms. These findings have important policy implications and suggest that the abolition of barriers preventing access to financing, as well as tax reforms and a consistent struggle against corruption may have a positive influence on the formalization of informal firms. On the other hand, firm owners should consider formalization to be a means to help them have greater opportunities for survival and growth.


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