Laboratory Testing Equipment Research Articles

How ready is the health care system in Northeast India for surgical delivery? a mixed-methods study on surgical capacity and need.

Surgical services are scarce with persisting inequalities in access across populations and regions globally. As the world's most populous county, India's surgical need is high and delivery rates estimated to be sub-par to meet need. There is a dearth of evidence, particularly sub-regional data, on surgical provisioning which is needed to aid planning. This mixed-methods study examines the state of surgical care in Northeast India, specifically health care system capacity and barriers to surgical delivery. It involved a facility-based census and semi-structured interviews with surgeons and patients across four states in the region. Abdominal conditions constituted a large portion of the overall surgeries across public and private facilities in the region. Workloads varied among surgical providers across facilities. Task-shifting occurred, involving non-specialist nursing staff assisting doctors with surgical procedures or surgeons taking on anaesthetic tasks. Structural factors dis-incentivised facility-level investment in suitable infrastructure. Facility functionality was on average higher in private providers compared to public providers and private facilities offer a wider range of surgical procedures. Facilities in general had adequate laboratory testing capability, infrastructure and equipment. Public facilities often do not have surgeon available around the clock while both public and private facilities frequently lack adequate blood banking. Patients' care pathways were shaped by facility-level shortages as well as personal preferences influenced by cost and distance to facilities. Skewed workloads across facilities and regions indicate uneven surgical delivery, with potentially variable care quality and provider efficiency. The need for a more system-wide and inter-linked approach to referral coordination and human resource management is evident in the results. Existing task-shifting practices, along with incapacities induced by structural factors, signal the directions for possible policy action.

DEM analysis of constrained modulus nonlinearity and damping factor of dry granular soils

The seismic site response analysis requires the dynamic soil properties (i.e., the modulus and damping). While it is well understood that the shear modulus and damping ratio are nonlinearly shear-strain dependent, the knowledge on the constrained modulus and damping ratio of compressional waves is still very limited due to lack of laboratory testing equipment. This study aims to simulate cyclic tests of constrained compression for granular specimens by discrete element method (DEM) to understand the dynamic soil properties of compressional waves, i.e., the nonlinearity in constrained modulus and damping ratio with the compression strain. The evolution in microstructure of granular specimens is revealed to provide micromechanical interpretations for the compressional soil nonlinearity. The results show that the dependency of constrained modulus on compression strain is different in compression and extension stages, and the modulus reduction is only observed in the extension path. The damping ratio of samples under cyclic constrained compression is smaller than that of cyclic shear. The nonlinear soil behavior is more obvious at lower confining pressure and for dense sample. The nonlinearity of constrained modulus depends on the coordination number, contact normal force and fabric anisotropy, while the associated damping ratio is only related to fabric anisotropy.

Coagulation Function Testing Clinical Demand and Current Status in China

Diseases or symptoms related to coagulation function are widely present in clinical daily work, as coagulation function plays a central role in maintaining homeostasis in the internal environment. Therefore, coagulation dysfunction often leads to serious harm to patients. At the same time, coagulation related treatments such as the use of anticoagulants or transfusion therapy have potential serious side effects, even leading to patient death. For many years, balancing the bleeding or embolism caused by anticoagulants has been a challenge that clinical workers have to face, which poses great challenges to clinical work. Therefore, monitoring coagulation function is very important for clinical diagnosis and treatment. The rapid and accurate completion of coagulation function diagnosis conclusions and early transmission to clinical workers are important guarantees for patient life. However, at present, due to technical limitations and the complexity of the detection process, this demand cannot be met. At present, in China, coagulation function testing is mostly concentrated in laboratory departments, and the limitation of distance may affect the timeliness of coagulation function testing. Therefore, many clinical departments of institutions tend to conduct coagulation function testing themselves, which has led to many new demands for coagulation function testing, such as fast and convenient POCT coagulation function testing and coagulation function testing of cell models that are more in line with clinical needs, More joint detection of coagulation markers and so on, of course, these needs must be established on the premise that clinical testing equipment and laboratory testing results are consistent. However, in order to meet the needs of miniaturization and rapid testing, the coagulation function testing equipment used in clinical departments often has significant methodological differences from laboratory testing equipment, which further leads to differences in testing results. Based on this situation, many new technologies, including microfluidic technology, as well as more detection techniques, have been widely and deeply applied to clinical coagulation function testing, which has brought a lot of good news to clinical coagulation function diagnosis to a large extent.

Technology Focus: Formation Damage (March 2023)

Identification, prevention, and remediation of formation damage during the life cycle of oil and gas wells are key for our industry to allow wells to perform to their full potential. Increased awareness of potential damage mechanisms along with improvements in laboratory testing equipment and methodologies have proven to be instrumental in efficient prevention and remediation of formation damage in production and injection wells in conventional reservoirs. While the ongoing technical studies and technology developments in the area of formation damage are heavily focused on key damage-mechanism scenarios during drilling and production, such as drilling-fluid-induced damage, scaling, clay swelling, fines migration, and incompatibility of fluid/fluid and fluid/rock in conventional sandstone and carbonate reservoirs, there are new research activities and increased applications of learnings in low-permeability unconventional reservoirs and carbon capture and storage (CCS). In low-permeability unconventional reservoirs, hydraulic fracturing has proven instrumental for economic and successful development. Injection of a large volume of fracturing fluid water is necessary to place the required quantity of proppant to generate and maintain fracture conductivity, thereby increasing the risk of fracturing-fluid-induced formation damage. New laboratory studies and field trials to select suitable preventive additives in fracturing fluid and optimize flowback processes are being deployed to prevent formation damage not only from gelling materials, friction-reducer chemicals, and water blockage but also from scaling and paraffin during production. Identification and prevention of formation-damage mechanisms affecting injectivity during CO2 injection in subsurface for CCS and CO2 enhanced oil recovery are critical. Enjoy the papers chosen this year, some of which highlight my comments and the innovation and successes achieved by our industry in identification, prevention, and remediation of formation damage in conventional reservoirs, which is expected to bring success in area of unconventional-reservoir development and carbon reduction. Recommended additional reading at OnePetro: www.onepetro.org. IPTC 22543 Formation Damage in the Hollín Sandstone: Diagnosis, Evaluation, and Stimulation Practices From Laboratory to Field Implementation, Sacha Field, Ecuador by Alvaro Izurieta, Halliburton, et al. SPE 208852 Understanding Fluid Exchange as Screens Are Run in Hole—Mitigation of Formation and Completion Damage Risks by Michael Byrne, Axis, et al. SPE 210763 Near-Wellbore Damage Associated With Formation Dry-Out and Fines Migration During CO2 Injection by Liam Alchin, The University of Adelaide, et al.

Development of a dynamic hollow cylinder apparatus for investigating the cyclic response of unsaturated soils subjected to stress anisotropy

The construction of most geo-structures like earthfill dams, roads, highways, embankments, and airport runways deals with the compaction of unsaturated soils under anisotropic cyclic/dynamic loadings. Many of these partially saturated geo-structures also experience three-dimensional dynamic loadings during service life. This paper presents a new hollow cylinder apparatus developed for the investigation of the cyclic response of unsaturated soils subjected to stress anisotropy. The device is unique as it enables, for the first time, studying the combined effects of stress anisotropy (effects of both parameters α and b) and the degree of saturation on the dynamic properties of unsaturated soils, the aspects that cannot be thoroughly captured using existing soil laboratory testing equipment. It allows independent control of the magnitudes and rotations of the principal stresses and measuring strains as well as control/measurement of pore water and pore air pressures in the unsaturated soil samples. The paper describes the main challenges and the adopted solutions for the development of the hollow cylinder apparatus, including the complexities associated with the non-uniformity of water content in the sample height and the measurement of the sample volume change. The relations for determining the effective stresses and strains in the unsaturated soil samples are also derived. The results of several dynamic tests on unsaturated sand over a wide range of shear strains are presented to demonstrate the capabilities of the apparatus.

Appling the Lean Six Sigma Methodology in of the CostManagement & Continuous Improvement of Performance (Applied Research in the Blood Laboratory of the Hussein Teaching Hospital)

Purpose: This study aims to enable measuring performance and its quality and seeks to improve performance, is that the research problem emerged in the emergence of poor results for patients' blood test cases due to delayed results of the analysis. Theoretical framework: This study adopted the deductive approach by relying on sources and references related to the literature of the topic directly, to benefit from them in enriching the theoretical aspect of the research. Design/methodology/approach: The inductive approach through the application of the applied analytical aspect, where the financial data for the year 2021 was obtained through financial accounts, production reports, inventory cards, quality reports, observations, and personal interviews, study sample at the Hussein Teaching Hospital's blood laboratory in the service sector represented by the Lean Six Sigma methodology. Findings: The blood laboratory at Al-Hussein Teaching Hospital did not rely on modern quality systems, including the agile Six Sigma methodology. There is a lot of wastage and loss in the specified standard time, which causes a lot of delay in the time of analysis, and this indicates the discrepancy and decentralization of the process. The laboratory testing equipment breaks down many times because of its old age (these devices were obtained from the Japanese grant during the year 2003), and this causes two or three re-examinations, which drains additional time. As well, the small area of the laboratory compared to the number of visitors. Research, Practical & Social implications: The research enables measuring performance and its quality and seeks to improve performance, is that the research problem emerged in the emergence of poor results for patients' blood test cases due to delayed results of the analysis. The Hussein Teaching Hospital's blood laboratory is the service sector represented by the Lean Six Sigma methodology. In order to implement continuous improvement in the area of medical staff quality and to simultaneously provide the right environment for continuous improvement, Originality/value: This study is one of the very few studies that focus on the concept of Six Sigma as one of the tools of the modern quality management system, which is concerned with diagnosing and treating deviations to improve the performance of the blood test process, an attempt to manage cost through the use of accounting and statistical concepts, to achieve the highest levels of sigma.

Bayesian Approach To Improve The Confidence Of The Estimation Of The Shear Strength Of Coarse Mine Waste Using Barton’s Empirical Criterion

The evaluation of the shear strength of waste rock is required for the verification of the stability of high waste dumps, especially those that reach hundreds of meters in height. Mine waste rock material in open pit mining contains particles of metric scale which precludes the utilisation of commercial laboratory testing equipment. To overcome testing limitations, the shear strength of waste rock is frequently estimated using the empirical criterion of Barton-Kjærnsli. This criterion takes into consideration the nonlinearity of the shear strength envelope, characterising the behaviour of very coarse granular materials submitted to high loads. In the criterion, a stress-dependent structural component of the shear strength is parametrised with the equivalent roughness (R) and equivalent strength (S) and the structural component is added to the basic friction angle (φb) of the parental rock to determine the shear strength of the waste rock material. This paper demonstrates the use of Bayesian inference to determine the best set of parameters φb, R and S that satisfied both: large-scale laboratory testing results characterising a waste rock material, and reconciliation data from observations of stability of the waste dumps. The methodology allows the estimation of project-specific model parameters that honour both, laboratory data and site performance information. This objective is achieved through the estimation of correction factors to downgrade the strength from laboratory to field scale.

Design and Experimental Results of an Adaptive Fractional-Order Controller for a Quadrotor

The use of multi-copter systems started to grow over the last years in various applications. The designed solutions require high stability and maneuverability. To fulfill these specifications, a robust control strategy must be designed and integrated. Focusing on this challenge, this research proposes an adaptive control design applied to a physical model of a quadrotor prototype. The proposed adaptive structure guarantees robustness, control flexibility, and stability to the whole process. The prototype components, structure, and laboratory testing equipment that are used to run the experiments are presented in this paper. The study is focused on the performance comparison of a classical PID controller and a fractional-order controller, which are both integrated into the adaptive scheme. Fractional-order controllers are preferred due to their recognized ability to increase the robustness of the overall closed-loop system. Furthermore, this work covers the design and the tuning method of this control approach. The research concludes with the actual results obtained for this comparative study that highlights the advantages of the fractional-order controller.

Current Status of Cytomegalovirus Colitis Among Patients With Inflammatory Bowel Disease in China: A Questionnaire-Based Multicenter Study.

Cytomegalovirus (CMV) causes infection in patients with inflammatory bowel disease (IBD). This study investigated the prevalence of CMV colitis, the current status of laboratory testing equipment, and physicians' opinions regarding CMV and IBD in China. This retrospective multicenter study was conducted by Chinese members of the Asian Organization for Crohn's and Colitis and included 36 hospitals/institutes divided according to municipality, provincial capital city, and prefectural-level city. A survey questionnaire was administered, and chi-square and Fisher's exact tests were performed. A total of 4823 inpatients with ulcerative colitis (UC) and 4622 inpatients with Crohn's disease (CD) were included. The percentages of patients with moderate UC in the provincial capital city and municipality were significantly higher than that in the prefectural-level city (38.3% vs 29.1% and 40.1% vs 29.1%, respectively). The percentage of patients with mild CD was significantly lower in the provincial capital city than in the prefectural-level city and municipality (30.4% vs 40.3%; 30.4% vs 39.3%, respectively). There were 3.1% patients with UC and 0.8% patients with CD who had CMV colitis. The prevalence of CMV colitis was lower in patients with CD than in patients with UC (0.8% vs 3.1%). Of the 150 patients with UC and concurrent CMV colitis, 17.3% patients underwent surgery, 2.0% died, and 23.3% experienced complications. Punched-out ulcerations were the major characteristic features for detecting CMV colitis. Approximately 77.8% of hospitals possessed testing facilities capable of conducting CMV immunohistochemistry. CMV colitis is an important issue during the disease progression of IBD. However, improvement in knowledge and facilities is required to enhance the prognosis of patients.

Measuring the Interactions Between Health Demand, Informatics Supply, and Technological Applications in Digital Medical Innovation for China: Content Mapping and Analysis.

BackgroundThere were 2 major incentives introduced by the Chinese government to promote medical informatics in 2009 and 2016. As new drugs are the major source of medical innovation, informatics-related concepts and techniques are a major source of digital medical innovation. However, it is unclear whether the research efforts of medical informatics in China have met the health needs, such as disease management and population health.ObjectiveWe proposed an approach to mapping the interplay between different knowledge entities by using the tree structure of Medical Subject Headings (MeSH) to gain insights into the interactions between informatics supply, health demand, and technological applications in digital medical innovation in China.MethodsAll terms under the MeSH tree parent node “Diseases [C]” or node “Health [N01.400]” or “Public Health [N06.850]” were labelled as H. All terms under the node “Information Science [L]” were labelled as I, and all terms under node “Analytical, Diagnostic and Therapeutic Techniques, and Equipment [E]” were labelled as T. The H-I-T interactions can be measured by using their co-occurrences in a given publication.ResultsThe H-I-T interactions in China are showing significant growth and a more concentrated interplay were observed. Computing methodologies, informatics, and communications media (such as social media and the internet) constitute the majority of I-related concepts and techniques used for resolving the health promotion and diseases management problems in China. Generally there is a positive correlation between the burden and informatics research efforts for diseases in China. We think it is not contradictory that informatics research should be focused on the greatest burden of diseases or where it can have the most impact. Artificial intelligence is a competing field of medical informatics research in China, with a notable focus on diagnostic deep learning algorithms for medical imaging.ConclusionsIt is suggested that technological transfers, namely the functionality to be realized by medical/health informatics (eg, diagnosis, therapeutics, surgical procedures, laboratory testing techniques, and equipment and supplies) should be strengthened. Research on natural language processing and electronic health records should also be strengthened to improve the real-world applications of health information technologies and big data in the future.

RECOMMENDATIONS FOR EQUIPPING THE PROVING GROUND F OR TESTING ARMORED AND AUTOMOTIVE VEHICLES

Problem statement. Equipping the Armed Forces of Ukraine with new types of armament and military equipment, including armored and automotive equipment, leads to the need to create an appropriate proving ground: the development of infrastructure facilities, equipping with tools and equipment for laboratory tests, as well as means for monitoring the performance and determining the technical condition of armament and military equipment.
 Analysis of recent research and publications. Unfortunately, there are no recommendations in the existing publications on equipping the proving ground for armored and automotive vehicles.
 Statement of the task. The purpose of the work is to improve the efficiency of testing armored and automotive vehicles.
 The article defines the main tasks of the proving ground, proposes a relevant composition of its elements and general requirements for them, as well as proposals for equipping it with laboratory testing equipment.
 To solve the assigned tasks, the proving ground should include the following main objects and systems: a test area for armored and automotive vehicles; an area for testing samples of armored and automotive vehicles for survivability; complex of common use roads, special test roads; special facilities for the placement of laboratory testing equipment; engineering networks for testing and vital functions (power supply, water supply, etc.); systems of metrological, meteorological, fire protection and medical support, environmental safety; security system.
 Conclusions. The creation of a proving ground for armored and automotive vehicles will provide:
 building capacity of a test base of the Armed Forces of Ukraine for the assessment of promising models of armored and automotive vehicles;
 increasing the achieved level of control over the technical state of armaments and military equipment during tests;
 evaluation of the results of combat training with the combat use of armament and military equipment; accreditation of the proving ground for armament and military equipment in national and international conformity assessment and certification bodies for eligibility to carry out work in accordance with NATO standards.

Bending bad—testing caramel wafer bars (#TestATunnocks)

During the coronavirus pandemic, there have been significant challenges in the remote teaching and demonstration of experiments, especially those that require laboratory testing equipment. With a desire to give students a feel for our materials laboratory on open days and allow them to gain a deeper understanding of what materials science and engineering is about, we have designed an experiment focused on composite materials that can be performed remotely and without specialist equipment. This enabled students to experience a bend test sensorily through seeing, hearing and feeling it, creating a strong link to then being able to relate it to the pre-prepared experimental data taken in the laboratory. This fun, easy-to-run and engaging experiment allowed a shared experience and encouraged a discussion about students’ observations, differences in results and implications of the bend strength of sandwich composites. We have found it not only works well universally by all ages but can be used with younger children to think about words such as ‘stronger’, ‘stiffer’ and ‘flexible’ and how materials can be different in different directions.

Development of Rapid and High-Precision Colorimetric Device for Organophosphorus Pesticide Detection Based on Microfluidic Mixer Chip.

The excessive pesticide residues in cereals, fruit and vegetables is a big threat to human health, and it is necessary to develop a portable, low-cost and high-precision pesticide residue detection scheme to replace the large-scale laboratory testing equipment for rapid detection of pesticide residues. In this study, a colorimetric device for rapid detection of organophosphorus pesticide residues with high precision based on a microfluidic mixer chip was proposed. The microchannel structure with high mixing efficiency was determined by fluid dynamics simulation, while the corresponding microfluidic mixer chip was designed. The microfluidic mixer chip was prepared by a self-developed liquid crystal display (LCD) mask photo-curing machine. The influence of printing parameters on the accuracy of the prepared chip was investigated. The light source with the optimal wavelength of the device was determined by absorption spectrum measurement, and the relationship between the liquid reservoir depth and detection limit was studied by experiments. The correspondence between pesticide concentration and induced voltage was derived. The minimum detection concentration of the device could reach 0.045 mg·L−1 and the average detection time was reduced to 60 s. The results provide a theoretical and experimental basis for portable and high-precision detection of pesticide residues.

Measurement of Amount for Steel Abrasive Material Transported by Special Scraper Conveyor

Results obtained from measuring the required amount of steel abrasive material with various fragmentations, which is transported by a special kind of scraper conveyor, offers information that is useful for operators of the abrasive blast cabinets. The presented article describes an innovative methodology developed for determination of the most relevant operational parameters relating to the above-mentioned situation. The most important parameters in this case are: the optimal amount of the abrasive material, the conveying speed of the scraper conveyor and the feeding of the conveyor with regard to partial or full elimination of instable operational area. Elimination of the instable operational area is possible by means of a simple constructional modification of the given conveying system according to the results obtained from experimental investigation, which was performed using special, originally developed laboratory testing equipment.

COVID-19 Infection and Its Influence in Otorhinolaryngology-Head and Neck Surgery.

Introduction The novel coronavirus disease 2019 pandemic has rapidly spread worldwide, challenging healthcare resources and communities to an unprecedent degree. Simultaneously, the amount of clinical and scientific information released has overwhelmed journal platforms. Objectives This review aims to summarize the available diagnostic tools and current guidelines to safely assist patients while limiting the exposure of otolaryngologists during this pandemic. Data Synthesis Key articles were retrieved from the following databases: PubMed, Lancet, Springer Nature, BioMed Central, JAMA network and MEDLINE, as well as updated documents from the Spanish Ministry of Health, World Health Organization, Centers for Disease Control and Prevention, Spanish Association of Surgeons, ENT-UK, American College of Surgeons, and American Academy of Otolaryngology-Head and Neck Surgery. The terms used for the search were: COVID-19 , Test COVID , Surgery in COVID , 2019-nCoV , ‘ coronavirus’ , and SARS-CoV-2 . A total of 10,245 papers were retrieved. The inclusion criteria for the review included: COVID-19 testing ( n = 531), society guidelines for otolaryngology-head and neck surgery patient care in the outpatient clinic ( n = 10) and surgical ( n = 18) settings. Studies not related to COVID-19 diagnosis were excluded. Conclusion Healthcare institutions around the world are outlining their own protocols regarding laboratory testing and personnel protective equipment usage based upon medical societies recommendations during the COVID-19 pandemic. We have summarized the available laboratory tests and their respective sensitivity and specificity. Moreover, clinical guidelines from different societies were reviewed and summarized to facilitate guidance for otolaryngologists in the operating room and in the clinical settings.

Tindak Pidana Peredaran Pemalsuan Obat Berdasarkan Undang-Undang Nomor 36 Tahun 2009 tentang Kesehatan

The purpose of this research is to find out about the Regulations for the Crime of Drug Counterfeiting According to Law Number 36 Year 2009 concerning Health, How is the Responsibility for the Crime of Drug Counterfeiting According to the Criminal Code and Law Number 36 Year 2009 Regarding Health and Obstacles That Become BPOM's Obstacles in Handling Drug Counterfeiting Crime. Methods This type of research in writing this thesis uses normative juridical research. The data of this study are secondary data, the collection technique is aligned with the nature of the research. The nature of the research is normative legal research and research is analyzed qualitatively, meaning that the existing data is analyzed in depth, holistically and comprehensively. The conclusion of this research is that the regulation regarding the criminal act of drug counterfeiting in the Indonesian Criminal Code Article 386 Paragraph (1) is prohibited from selling, offering or delivering drugs known to be counterfeited, with a maximum imprisonment of 4 (four) years. Law Number 36 Year 2009 Concerning Health, namely Article 196, Article 197, Article 198, Article 199, Article 201. Law Number 36 Year 2009 Concerning Health, criminal responsibility lies with the individual or the person, the criminal responsibility is given to the form of a fine 3 ( three) times the penalty is imposed, as well as additional penalties in the form of administrative sanctions. The constraints faced are the intensity of supervision, lack of compliance with procedure requirements, limited human resources, limited laboratory testing equipment.

Instrumentation of heavy-duty asphalt slabs for wheel tracking experiment

Laboratory testing equipment for asphalt mixtures with three different functionalities is introduced. The rotary compactor and wheel tracker (RCWT) not only achieves realistic contact areas of actual pneumatic tyres but can also compact heavy-duty laboratory asphalt mixtures to the desirable density and conduct simulated wheel tracking tests (WTTs). The RCWT is able to replicate stone mastic asphalt full-scale site rollers. The simulated WTT, with actual pneumatic tyres, reproduced the non-uniform contact stresses as well as other non-linear and viscoelastic behaviours of the tyre–pavement interaction. Furthermore, the instrumentation system with fully calibrated sensors and data acquisition set-up captured all the crucial factors – including the temperature inside the asphalt mixture mat, vertical load, rutting depth and vertical compressive strain at the bottom of the asphalt layer – effectively and continuously.

Influence of amygdale on crack evolution and failure behavior of basalt

Amygdaloidal basalt is one of the two major types of surrounding rocks that are widely exposed in the super large-scale underground powerhouse caverns of Baihetan Hydropower Station, China. Excavation of the caverns induced a series of mechanical responses, including cracking and fracture relaxation. This study comprehensively explored the deformation and failure characteristics and the fracture evolution process of the amygdaloidal basalt using conventional MTS triaxial laboratory testing equipment and continuous–discontinuous modeling (FDEM) with the aim of clarifying its failure mechanism. The research results indicate that: (1) amygdales significantly changed the deformation and failure characteristics of basalt. Whereas the post-peak mechanical behavior of cryptocrystalline basalt was brittle, that of amygdaloidal basalt was brittle under low confining stresses and ductile under high confining stresses. Meanwhile, whereas the failure mode of cryptocrystalline basalt was fragmentation failure, that of amygdaloidal basalt was splitting failure at low confining stresses and shear failure at high confining stresses. (2) An FDEM model considering the heterogeneity of the rock mesostructure was established based on the statistical laws of the amygdales in real samples, and this confirmed the stress–strain curve characteristics, failure modes, and characteristic strengths measured in laboratory tests. (3) A complicated inhomogeneous stress field formed readily around amygdales and had a significant effect on the fracture path. (4) With an increase in confining stresses, the degree of tensile stress concentration at the upper and lower tips of amygdales decreased and the lateral displacement became restricted. Consequently, the total number of micro-cracks and the ratio of tensile cracks to shear cracks decreased, the crack initiation mode changed from tensional cracking to shear cracking at the tips of the amygdale, and the distribution of crack orientations transitioned from an approximately vertical direction to preferential concentration along fracture planes. The research results form a solid foundation for the accurate understanding of the mechanical response and fracture mechanism of the rock surrounding underground powerhouse caverns at Baihetan hydropower station, and also provide a reference for the prediction of the mechanical properties of rock with flaws and the stability control of engineering rockmasses.

Alkaline Delignification of Cactus Fibres for Pulp and Papermaking Applications

Stable aqueous suspensions with high cellulosic contents and low fractions of lignin have been prepared from Cactus fibres via chemical delignification of the Cactus biomass feedstock with a sodium hydroxide–anthraquinone (soda–AQ) mixture. In order to optimize the reaction parameters, various temperatures between 120 and 170 °C and reaction times between 60 and 180 min were examined. The optimal yield of the resulting alkaline pulps (corresponding to the complete reaction of the raw materials) was equal to 41.4%, while the morphological parameters of individual cellulose fibres (such as length, width, and fraction of fine elements) were determined using a MorFi analyser. The estimated degree of polymerization, water retention value, total charge, and drainability of the produced pulps confirmed their suitability for papermaking applications; as a result, paper sheets were manually prepared using a Rapid-Kothen sheet former apparatus. The morphological analysis of the produced paper was conducted using a scanning electron microscopy technique, and its structural and mechanical properties were evaluated with the standard laboratory testing equipment. The obtained results indicate that the paper fabricated from Cactus fibres via the soda–AQ delignification process exhibits homogenous morphology as well as satisfactory mechanical and structural properties.

Conformity assessment of the measurement accuracy in testing laboratories using a software application* *This paper was accepted for publication in Proceedings after double peer reviewing process but was not presented at the Conference ROTRIB’16

This article presents a method for assessing the accuracy of the measurements obtained at different tests conducted in laboratories by implementing the interlaboratory comparison method (organization, performance and evaluation of measurements of tests on the same or similar items by two or more laboratories under predetermined conditions). The program (independent software application), realised by the author and described in this paper, analyses the measurement accuracy and performance of testing laboratory by comparing the results obtained from different tests, using the modify Youden diagram, helping identify different types of errors that can occur in measurement, according to ISO 13528:2015, Statistical methods for use in proficiency testing by interlaboratory comparison. A case study is presented in the article by determining the chemical composition of identical samples from five different laboratories. The Youden diagram obtained from this study case was used to identify errors in the laboratory testing equipment.