Numerical and Experimental Analysis of the Influence of Assembling Conditions and the Tolerance of Adapted Implantological Components on the Durability of the Prosthetic Construction

Durable fastening of implant retained prosthetic restorations, consisting of a series of elements, is one of the main factors of successful prosthetic rehabilitation. Clinically observed mechanical problems concerning the above mentioned components are complications that occur most often in the loading phase. The aim of this research was evaluation of the suppleness of the implant- -anti-rotary abutment construction to loosening under the influence of labile mechanical stress. Numerical analysis of resistance based on the finite element analysis (FEA) was used in the initial phase of this research. The actual tests were done with the use of a dynamic mechanical analyser Netzsch DMA 242 and a polarisation microscope equipped with a CCD camera. A series of implants connected with abutments composed of two parts were analysed. The results of initial studies utilizing the finite element analysis (FEA) allowed definition of the spheres of stress concentration. On the basis of in vitro experiments, the investigators evaluated the influence of tolerance of adapted implant-abutment interface fit, as well as the torque used in the assembly of the abutment, on the occurrence of micromovements and loosening of components. The results strongly indicate correlation between the chosen variables and the risk of occurrence of mechanical complications

Real-time placental vessel segmentation in fetoscopic laser surgery for Twin-to-Twin Transfusion Syndrome.

Twin-to-Twin Transfusion Syndrome (TTTS) is a rare condition that affects about 15% of monochorionic pregnancies, in which identical twins share a single placenta. Fetoscopic laser photocoagulation (FLP) is the standard treatment for TTTS, which significantly improves the survival of fetuses. The aim of FLP is to identify abnormal connections between blood vessels and to laser ablate them in order to equalize blood supply to both fetuses. However, performing fetoscopic surgery is challenging due to limited visibility, a narrow field of view, and significant variability among patients and domains. In order to enhance the visualization of placental vessels during surgery, we propose TTTSNet, a network architecture designed for real-time and accurate placental vessel segmentation. Our network architecture incorporates a novel channel attention module and multi-scale feature fusion module to precisely segment tiny placental vessels. To address the challenges posed by FLP-specific fiberscope and amniotic sac-based artifacts, we employed novel data augmentation techniques. These techniques simulate various artifacts, including laser pointer, amniotic sac particles, and structural and optical fiber artifacts. By incorporating these simulated artifacts during training, our network architecture demonstrated robust generalizability. We trained TTTSNet on a publicly available dataset of 2060 video frames from 18 independent fetoscopic procedures and evaluated it on a multi-center external dataset of 24 in-vivo procedures with a total of 2348 video frames. Our method achieved significant performance improvements compared to state-of-the-art methods, with a mean Intersection over Union of 78.26% for all placental vessels and 73.35% for a subset of tiny placental vessels. Moreover, our method achieved 172 and 152 frames per second on an A100 GPU, and Clara AGX, respectively. This potentially opens the door to real-time application during surgical procedures. The code is publicly available at https://github.com/SanoScience/TTTSNet

Preparation methods of calcium sulphate and urea adduct

The paper presents the results of laboratory studies on the preparation of calcium sulphate and urea adduct by: grinding, compacting and mixing in the presence of physical water. A method for the measurement of urea conversion into the adduct form, which is based on the difference in solubility of free urea and the adduct bound urea CaSO4ź4CO(NH2)2 in n-butanol, was developed. Mixing the reagents in the presence of physical water produced the best results. High urea conversion into the adduct form, over 85%, in the prepared samples indicates that this method can be successfully used to get CaSO4ź4CO(NH2)2 adduct

Utilization of Industrial Wastes in Fertilizer Industry. Possibilities and Implementation

Omówiono wyniki ważniejszych badań przeprowadzonych w Instytucie Nowych Syntez Chemicznych oraz w Instytucie Technologii Nieorganicznej i Nawozów Mineralnych Politechniki Wrocławskiej nad zagospodarowaniem odpadów z różnych działów gospodarki przy produkcji nawozów mineralnych. Wykazano, że duże ilości odpadów o znaczącej zawartości składników pokarmowych dla roślin, można wykorzystać do produkcji nawozów w charakterze źródła składników pokarmowych (np. siarczan potasu z produkcji biopaliw) czynnika uaktywniającego fosfor (np. kwas siarkowy z produkcji bieli tytanowej) a także jako źrodło składników pokarmowych i jako czynnika stabilizującego zawiesiny (np. szlam pofiltracyjny z oczyszczania kwasu fosforowego). Stwierdzono, że w dalszym ciągu, w skali świata pozostaje nierozwiązany problem fosfogipsu i przedstawiono koncepcję wykorzystania części fosfogipsu do produkcji nawozów azotowo-siarkowych z udziałem mocznika.The results of the most important studies conducted in the New Chemical Syntheses Institute and the Institute of Inorganic Technology and Mineral Fertilizers, Wroclaw University of Technology on waste management in different sectors of the economy in the production of mineral fertilizers. It has been shown that large amounts of waste with a significant content of nutrients for the plants can be used for the production of fertilizers as a source of nutrients (eg. Potassium sulphate from the production of biofuels) agent that activates phosphorus (eg. sulfuric acid from the production of titanium dioxide), and also as a source of nutrients and as a slime stabilizing agent (eg. the filter sludge from the purification of phosphoric acid). It was found that problem of phosphogypsum continues to remain unsolved worldwide and the concept of using part of phosphogypsum to produce fertilizer nitrogen and sulfur with the participation of urea was introduced

Studies on the screw granulation of fertilizers on the basis of urea and calcium sulfate adduct

Przedstawiono wyniki badań nad możliwością wytwarzania nawozów typu adduktu siarczanu wapnia i mocznika na bazie fosfogipsu metodą granulacji ślimakowej. Do badań wykorzystano wytłaczarkę jednoślimakową. Stwierdzono, że poprzez wytłaczanie można uzyskiwać produkty o wysokim stopniu przereagowania mocznika w formę adduktu (ponad 80%). Uzyskane granulaty cechowała bardzo wysoka wytrzymałość mechaniczna.Results of studies on preparation possibility of fertilizers of calcium sulfate and urea type from phosphogypsum with screw granulation method are presented. One screw extruder was used in the studies. It was found that products of high degree of urea conversion into the adduct form (over 80%) can be obtained by extrusion. The prepared granular product had very high mechanical strength

Utilization of waste gypsum in fertilizer production

The results of the study regarding utilization of the waste gypsum formed as a by-product during the production of the magnesium sulphate from dolomite have been presented. The use of this waste have been proposed for the production of granulated multi-component fertilizers containing 25% N; 8% S; 14% CaO and 3.5% MgO. In the process of fertilizer production, the urea which will be bounded with the calcium and magnesium sulphate from the waste in the form of adducts of CaSO4 . 4CO(NH2)2 and MgSO4 . CO(NH2)2 . 3H2O will be the source of nitrogen in the fertilizer. It has been stated on the basis of the laboratory tests that the fertilizer with the assumed composition can be obtained by means of granulation of the raw material pulp, along with the dried and ground product return. The possibility of the production of the fertilizer with good physical properties according to the assumed concept has been confirmed in the pilot scale

Utilization of waste gypsum in fertilizer production

The results of the study regarding utilization of the waste gypsum formed as a by-product during the production of the magnesium sulphate from dolomite have been presented. The use of this waste have been proposed for the production of granulated multi-component fertilizers containing 25% N; 8% S; 14% CaO and 3.5% MgO. In the process of fertilizer production, the urea which will be bounded with the calcium and magnesium sulphate from the waste in the form of adducts of CaSO4 . 4CO(NH2)2 and MgSO4 . CO(NH2)2 . 3H2O will be the source of nitrogen in the fertilizer. It has been stated on the basis of the laboratory tests that the fertilizer with the assumed composition can be obtained by means of granulation of the raw material pulp, along with the dried and ground product return. The possibility of the production of the fertilizer with good physical properties according to the assumed concept has been confirmed in the pilot scale

Production technology of nitrogen-sulphur-calcium fertilizers on the base of urea and phosphogypsum

Przeprowadzono badania nad możliwością otrzymywania granulowanych nawozów typu adduktu siarczanu wapnia i mocznika na drodze granulacji pulpy mocznikowo-fosfogipsowej. Zbadano wpływ różnych dodatków na wytrzymałość granul tego typu nawozów. Stwierdzono, że dodatek siarczanu magnezu, stosowanego w różnych formach, zwiększa wytrzymałość granulatów. Wzrost wytrzymałości powoduje także dodatek bentonitu. Przydatność rolnicza nawozu została sprawdzona w rolniczych doświadczeniach polowych.Studies on preparation possibility of granular fertilizers of calcium sulfate and urea adduct type by granulation of urea-phosphogypsum pulp were carried out. The effect of various additives on granule hardness of this type fertilizers was investigated. It was found that addition of magnesium sulfate in various forms increased the granule mechanical strength. Bentonite addition also increased hardness of granules. Agricultural usefulness of the fertilizers was confirmed in field tests

Effect of CORONA treatment on physical properties of linen fabric

This poster will present the newest results of research refer to linen fabrics physical properties without and after CORONA treatment. Corona treatment is a new method in textile finishing technology. Fabrics after Corona get new better properties, which make finishing processes much easier. Quality of fabrics after Corona can be highly improved in relevant aspects concerning safety of users (flame retardancy), comfort (touch and hydrophilization of softened materials), and easy care (less shrinkage, better crease recovery in no-iron behavior and less formaldehyde). Corona give a chance to get better end properties at lower costs and less environmental aggression

The Influence of Elastic Components of the Venous Wall on the Biomechanical Properties of Different Veins Used for Arterial Reconstruction

AbstractObjectiveTo evaluate the relationship between the biomechanical properties and the structure of elastic components in different veins used for vascular reconstruction.DesignIn vitro experimental study.Material and methodsGroups of 30 samples of incompetent saphenous veins (rSV), competent saphenous veins (cSV) and femoral veins (FVs) were compared following immunohistochemical staining for the presence of collagen types I, III and IV and elastin. The percentage area of transverse section of veins occupied by each type of collagen and elastin was measured using a computer-image-analysis system connected to a microscope. For all three groups of veins, the storage modulus, E′, and the loss modulus, E′′, were measured with a mechanical analyser, DMA-242, and changes in the function of temperature and frequency, and duration of exposure to the applied force were determined.ResultsThe rSV showed the highest percentage share of collagen I and the lowest percentage share of collagen IV. These samples also showed the greatest expression of elastin and the highest elastin to collagen ratio. The rSV were also found to have the highest E′ and E′′, and during the long-term exposure achieved maximum stiffness in the least time as compared to cSV and FV.ConclusionThe histological structure directly influences the biomechanical properties of venous wall with rSV showing least compliance and cSV the greatest compliance