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PL
W artykule przedstawiono wyniki badań, jakie prowadzone były w celu określenia wpływu stopnia perforacji płyty czołowej nawiewnika stosowanego w systemach wentylacji indywidualnej, na charakterystykę nawiewanego przez ten element strumienia powietrza, tj. profil prędkości oraz stopień turbulencji. Doświadczenia prowadzono z wykorzystaniem trzech nawiewników o różnym stopniu perforacji płyty czołowej, przy stałym strumieniu objętości powietrza 20 l/s.
EN
Research results are presented concerning an influence of the perforation of the ventilator front panel on the airflow characteristics in the individual ventilation systems. The characteristics includes turbulence level and velocity profile. The experiments have been carried out with three ventilator units having various perforations of the front panels and with constant air flux of 20 l/s.
EN
Background Duodenal diverticula affect a large part of the population. It is a congenital abnormality that develops over time. The incidence of duodenal diverticulum is estimated at 22% of the population in autopsies. Only 5% of patients present symptoms, and of those only 1%–2% require surgery.Material and methodsTwo patients are described who underwent surgery due to duodenal diverticulum perforation mimicking acute cholecystitis.ResultsPerforation of the duodenal diverticulum, combined the difficulty of treatment and potential for complications, is a disease with a high mortality rate. It is subtle and difficult to diagnose due to the lack of generalized peritonitis and unspecific symptoms. The rarity and the wide spectrum of the disease, in combination with additional factors to be considered in treating this disease, mean there is no standard treatment. Depending on the patient's general condition, disease advancement, age and pathological findings observable only during surgery, we can choose between conservative treatment and a wide spectrum of surgeries.ConclusionsDuodenal diverticular disease rarely gives any symptoms. However, even after the onset of symptoms, only 1-2% of patients require surgery. Our work is unique because we present two cases, each featuring different approaches - conservative and surgical.
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Content available remote Diverticulitis of the Small Bowel
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EN
In contrast to diverticulosis of the large bowel, diverticular disease of the small bowel is rare. This small bowel disease is predominantly localized to the duodenum. Jejunal and ileal diverticula are rare and occur in the majority of patients without clinical impact. Less than 10% of patients develop serious complications, including obstruction, hemorrhage, perforation and penetration. Here, we present 4 patients with jejunal diverticulitis. Three of these patients experienced perforation.
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Content available remote Neuroendocrine Carcinoma Responsible For Gastrointestinal Tract Perforation
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In terms of their clinical and histopathologic presentation, neuroendocrine gastrointestinal tumours constitute an extremely diversifed group of malignancies and thus are difficult to diagnose. Late and often accidental diagnosis means a multistage therapeutic process. The authors present the case of a 78-year-old female patient with clinical symptoms of visceral perforation followed by diffuse peritonitis. The patient was immediately operated. Intraoperative presentation revealed annular narrowing of the intestinal lumen by a tumour located in the cecum just above Bauhin's valve. The free tenia was microperforated in the described lesion area and had been the primary cause of diffuse fibrinous and pyogenic peritonitis. In addition, choleliths were found in the gallbladder. Right hemicolectomy with regional lymphadenectomy and cholecystectomy were performed. No postoperative complications. Histopathologic examination of resected specimen returned carcinoma neuroendocrinale. The authors argue, that the uncommon clinical course and circular, closing growth of the small cecum-located tumour with coincident perforation may originally suggest non-epithelial disease background.
EN
Introduction: Chest pain is one of the most common symptoms with which patients report to the doctor. The reason for this is the fear of the sick, who often equate this symptom with dangerous diseases such as heart attack. The primary source of pain does not always have to be located within the chest. Colon perforation is a rare but possible complication of colonoscopy, which may result in free gas entering the mediastinum which is accompanied by chest pain. Case report: We present the case of a 78-year-old woman who reported to the hospital emergency department with chest pain, shortness of breath and abdominal pain. On the basis of imaging examinations, perforation of sigmoid affected by diverticulosis, complicated by pneumomediastinum and retroperitoneal emphysema, was suspected. The aforementioned ailments were caused by iatrogenic perforation of the sigmoid during diagnostic colonoscopy performed on an outpatient basis a few hours before reporting to the hospital. The patient was urgently qualified for laparotomy. Intraoperatively, perforation was confirmed at the rectosigmoid junction, which was the cause of retroperitoneal and pneumomediastinum with rightsided emphysema of the lateral neck region. No fluid or intestinal contents were found in the abdomen. The sigmoid colon and upper rectum were resected via double-stapled anastomosis performed between the descending colon and rectum. The patient was discharged home in good condition on the 7th postoperative day. Conclusions: Colonoscopy is a diagnostic and therapeutic procedure that is considered relatively safe, but also carries complications such as bleeding or perforation of the large intestine. Diverticular disease is a common condition which most often affects the sigmoid colon. In areas of the weakest resistance, diverticulum formation occurs as a result of increased intra-abdominal pressure, which is an additional risk factor for perforation during colonoscopy. It is important to remember the possible different clinical presentation of gastrointestinal perforation, which may also manifest as chest pain. With early detection and surgical treatment, life-threatening complications associated with the development of pneumothorax can be avoided.
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Content available remote Perforated Gist of Meckel's Diverticulum
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EN
Meckel diverticulum is the most common congenital abnormality of gastrointestinal track (2-4%), however complications occur rarely (4-16%). We describe a case of 63- years old female presenting simultaneously two serious complications of Meckel diverticulum. Operated patient was diagnosed with perforated tumor of Meckel diverticulum. Segmental resection of small bowel including tumor was performed. Pathology examination revealed gastrointestinal stromal tumor (GIST) in Meckel diverticulum. No significant malignancy risk factors were found (low mitotic count). Consequently, computed tomography periodic surveillance was implemented.We report the possibility of simultaneous presentation of two serious complications of Meckel diverticulum. Tumors of Meckel diverticulum may mimic other abdominal pathologies and thus, they should be considered in differential diagnosis of abdominal tumors.
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Content available Perforated gist of Meckel’s diverticulum
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EN
Meckel diverticulum is the most common congenital abnormality of gastrointestinal track (2-4%), however complications occur rarely (4-16%). We describe a case of 63- years old female presenting simultaneously two serious complications of Meckel diverticulum. Operated patient was diagnosed with perforated tumor of Meckel diverticulum. Segmental resection of small bowel including tumor was performed. Pathology examination revealed gastrointestinal stromal tumor (GIST) in Meckel diverticulum. No significant malignancy risk factors were found (low mitotic count). Consequently, computed tomography periodic surveillance was implemented. We report the possibility of simultaneous presentation of two serious complications of Meckel diverticulum. Tumors of Meckel diverticulum may mimic other abdominal pathologies and thus, they should be considered in differential diagnosis of abdominal tumors.
EN
Cone beam computed tomography (CBCT) imaging is useful in various clinical situations including assessing dental morphology prior to endodontic treatment, locating tooth perforations, separated endodontic files, and resorptions. The aim of this paper was to present the usefulness of CBCT in endodontic treatment planning, through the review of two complicated endodontic cases. Two cases of failed endodontic treatment were presented in which CBCT allowed for correct diagnosis, as well as endodontic treatment qualification and planning. CBCT is especially useful when assessing endodontic treatment complications such as overextended root canal obturation material, separated endodontic instruments, and/or localization of perforations. Having the pros of CBCT in mind, one always has to weigh the added diagnostic value of CBCT with the economic cost of the tool employed, in order to make the best informed decision regarding accurate diagnosis and treatment.
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Content available remote Influence of veneer perforation on 2D formability of two-layer material
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EN
The aim of the paper is to investigate the effect of different perforations in veneers on the 2D formability of two-layer material. Veneer perforation was done with a CO2 laser. The two-layer material was composed of two veneers, one perforated and one entire (non-perforated), the fibers in the veneers being perpendicular to one another, and was glued using a polyethylene film. The 2D (planar) formability of two-layer materials was detected by three-point bending load and evaluated through the minimum bending radius. The most significant improvement of formability wasobserved after perforation in the shape of the letter "I" at the perforation direction parallel to the wood grain.
EN
The porosity in metals has been perceived only as a negative factor for a long time, which reduces the mechanical properties and tightness of the material. For preventing and blocking the negative effects of porosity in metals were dedicated a lot of scientific works, some of them are used in present time [1-3]. However, due to numerous experiments the positive factors of porosity in metals were opened. These factors are the combination of physical and mechanical properties such as high stiffness in combination with a very low density (low specific gravity) and/or high gas permeability combined with a high/low thermal conductivity [4]. Thanks to this, porous metals have received a new stage of evolution. Now porosity is being regarded not only as a negative effect of imperfection technology of making metal products, but also as a way to produce a material with unique properties. Globally porous metal materials can be divided into three categories: cellular metals [5]; metallic foams [6] and porous metals [7]. Products from such materials are used in the automotive industry as structural elements; in the aerospace industry as titanium and aluminum sandwich panels; in shipbuilding as a body for passenger vessels; in medicine as implants in humans [8-11]. From the field of use such products must conform to the following parameters: porosity, gas permeability, thermal conductivity, electrical conductivity, density, sound absorption, etc. There are a lot of methods of creation of porous metallic materials today. But complete method of controlling thermal properties of materials by changing parameters of porosity is still no. For creating such method we need to know what factors, under what conditions and with what degree are influence on the required material's parameters. The aim of this work is to investigate the influence of a combination of factors (form, size and position of pores) in the porous metal material on the thermal conductivity.
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Content available remote Influence of veneer perforation on 2D formability of two-layer material
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EN
The aim of the paper is to investigate the effect of different perforations in veneers on the 2D formability of two-layer material. Veneer perforation was done with a CO2 laser. The two-layer material was composed of two veneers, one perforated and one entire (non-perforated), the fibers in the veneers being perpendicular to one another, and was glued using a polyethylene film. The 2D (planar) formability of two-layer materials was detected by three-point bending load and evaluated through the minimum bending radius. The most significant improvement of formability was observed after perforation in the shape of the letter "I" at the perforation direction parallel to the wood grain.
EN
Some selected parameters of steel for structural-ballistic shields (OKB) used in the Navy vessels have been presented. The standards for steel to be used for ballistic shields are established by safety standards institutions and committees. There has been made an analysis of steel used for OKB of the vessels. The bullet-proof of the platters has been carried out on the appropriate position. The results of bullet-proof test of selected platters have been presented. The analysis made allowed to select the platters used for the structural-ballistic safety shields in marine vessels and give the direction for further research determined by contemporary threats of both military and terroristic nature. To produce the platters there have been used two types of armoured metal sheet which had been milled to flats made of the basic steel and which can be applied in shipbuilding. The structural-ballistic platters have had the form of flats with the total thickness of 8.5-9.2 mm. The prepared structural-ballistic platters have been technological processed in order to increase the degree of their strength. There have been also presented mechanical and technological properties of platters after heat treatment. The results of the bullet-proof have been presented in graphs form defining the dependence between the hit force and time. The effects of fire of specimen made of platters, by 7.62 mm cal. bullets with the proper speed have been seen on photographs.
PL
Zabiegi perforacji, których zasadniczym celem jest przygotowanie otworu do wykonania w nim w kolejnym etapie zabiegów intensyfikacji przypływu muszą być projektowane ze szczególnym uwzględnieniem specyfiki planowanego zabiegu intensyfikacji (np. szczelinowanie hydrauliczne, szczelinowanie ciśnieniem gazów prochowych, kwasowanie, itp.). W artykule dokonano przeglądu problematyki tematu ze zwróceniem szczególnej uwagi na kryteria zabiegu perforacji wykonywanej jako przygotowanie do operacji intensyfikacji wydobycia.
EN
Perforating jobs carried out with the main aim to prepare borehole for subsequent production intensification treatments, must be designed while particularly considering specifics of planned intensification treatment (e.g. hydraulic fracturing, treatment with using powder charge pressure generators, acidizing, etc.). In the study literature review of the subject matter was given with particular attention put to criteria of perforating jobs carried out as pre-intensification treatment perforation.
EN
Colonoscopy is a routine diagnostic and therapeutic procedure. Along with the increase in the complexity of the procedures performed, the risk of complications increases. In 2017, WSES (World Society of Emergency Surgery) published the principles of safe colonoscopy. Intestinal perforation is one of the most common complications. The risk of perforation in treatment procedures such as mucosectomy or endoscopic dissection is significantly greater than the risk of diagnostic colonoscopy. The basic rule of the procedure in case of suspected perforation is close supervision over the patient’s condition and the soonest possible repair of damage. The role of the endoscopist is not only early recognition, but also early treatment of damage. Immediate endoscopic treatment of lesions is an effective, final and acceptable management strategy. In patients who have undergone imaging diagnostics for another reason, free gas in the peritoneal cavity can be recognized. It does not have to mean the need for urgent surgical intervention. Patients with asymptomatic pneumoperitoneum after colonoscopy should, however, be treated as patients with suspected perforation of the large intestine and undergo careful clinical observation in accordance with WSES recommendations. Colonoscopy is a procedure with a risk of complications, which should be reported to patients qualified for endoscopy, but appropriate management reduces the risk of morbidity and mortality associated with this procedure.
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PL
Zabiegi perforacji, których zasadniczym celem jest przygotowanie otworu do wykonania w nim w kolejnym etapie zabiegów intensyfikacji przypływu, jakkolwiek w swej zasadzie podobne do perforacji udostępniającej, muszą jednak być projektowane ze szczególnym uwzględnieniem specyfiki planowanego zabiegu intensyfikacji (np. szczelinowanie hydrauliczne, szczelinowanie ciśnieniem gazów prochowych, kwasowanie, itp.). W artykule dokonano przeglądu problematyki tematu, ze zwróceniem szczególnej uwagi na kryteria zabiegu perforacji wykonywanej jako przygotowanie do operacji intensyfikacji wydobycia. Przedstawiono również syntetyczne ujęcie zasad projektowania zabiegów perforacji przygotowującej intensyfikację wydobycia, zapewniających uzyskanie najlepszego efektu – zabiegów zazwyczaj kosztownych, często poprzedzanych jeszcze bardziej kosztowną rekonstrukcją otworu.
EN
Perforating jobs carried out with the main aim to prepare borehole for subsequent production intensification treatments, in their principle similar to completion perforations, must be, however, designed while particularly considering specifics of planned intensification treatment (e.g. hydraulic fracturing, treatment with using powder charge pressure generators, acidizing, etc.). In the study literature review of the subject matter was given with particular attention put to criteria of perforating jobs carried out as pre-intensification treatment perforation. The authors gave synthetic formulation of pre-intensification treatment perforation designing, ensuring obtaining of the best results from – usually expensive – intensification treatment, which must frequently be preceded by even more costly workover.
PL
W pierwszej części artykułu zostanie przedstawiony model matematyczny pośredniego, regeneracyjnego wymiennika wyparnego o perforowanej powierzchni przegrody oddzielającej kanał suchy od mokrego. W artykule tym przedstawiono algorytm obliczeniowy opisujący procesy mieszania się strumienia pomocniczego ze strumieniem głównym w roboczych kanałach rekuperatora. W następnej części artykułu przedstawione zostaną wyniki symulacji numerycznej.
EN
The first part of following paper presents a mathematical model of indirect evaporative regenerative heat exchanger with perforated plate surface separating the dry and wet channel. Calculation algorithm describing the process of mixing the secondary and main streams in the working channel is shown. In the next part of following paper the results of numerical simulation will be presented.
PL
Wykonanie perforacji w otworze wiertniczym jest niezbędne by umożliwić napływ płynu złożowego do odwiertu i dalszy jego przepływ na powierzchnię. Zabieg perforacji oparty na detonacji materiału wysokoenergetycznego powoduje jednak obniżenie współczynnika przepuszczalności w strefie przy otworowej, co wpływa negatywnie na produktywność/chłonność odwiertu. Ogół czynników determinujących obniżenie przepuszczalności w strefie trzyotworowej nazwano efektem skinu. W pracy tej, autorzy przybliżają mechanizm powstawania skin-efektu jako składowej pochodzącej z zabiegu perforacji, oraz jego wpływ na efektywność pracy odwiertu.
EN
The perforation of wellbore casing is essential to allow the reservoir fluid inflow to the wellbore and further up to the surface. The perforation job employing high-energy material, results, however, in decreasing the permeability factor in the near-wellbore zone, which negatively influences productivity/injection ability of the wellbore. General set of factors determining permeability depletion within the near-wellbore zone has been called skin-effect. In this study the authors will give a closer look into the skin-effect creation mechanism as a constituent induced by perforating job, as well as its influence on further wellbore operation.
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Content available remote Perforation modes of metal plates struck by a blunt rigid projectile
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EN
The present paper analyzes the possible modes of shear plugging and adiabatic shear plugging in the perforation of metal plates struck by a blunt rigid projectile. The modified ballistic limit and residual velocity under the condition of adiabatic shear plugging are further formulated. Further experimental analyses are conducted on the perforations of Weldox E steel plates in order to discuss the effects of plate thickness and material strength/hardness on the terminal ballistic performance. More experimental evidence confirms the jump of residual velocity at the ballistic limit induced by the structural response of the plate. With increasing the thickness of plate and the material strength, failure modes of the plate may transform from shear plugging to adiabatic shear plugging.
PL
W artykule podjęto próbę wskazania parametrów, które w istotny sposób wpływają na efektywność prac perforacyjnych, a związane są z koniecznością ograniczenia wymiarów zewnętrznych sprzętu strzałowego. Przedstawiono ładunki kumulacyjne o różnej geometrii, jako kluczowy element perforatora oraz wskazano skutki ograniczenia ich wymiaru zewnętrznego, wraz z wynikami symulacji komputerowej. Autor omawia główne parametry geometryczne projektowania perforatora małośrednicowego, do których zaliczył: gęstość perforacji, kąt przesunięcia fazowego oraz głębokość kanału perforacyjnego. Omówiony został wpływ wyżej wymienionych czynników na skuteczność zabiegu perforacji w oparciu o wskaźnik produktywności odwiertu oraz zjawisko Skin Efektu.
EN
Until recently the drilling operation in Poland was carried out at not demanding geological condition. As the time went by the exploration had been made in more rough condition, and it was followed by change of technical equipment and well completion. This work outline the need of designee a shooting tools with limited diameter which can be used by exploitation pipes. Author indicates the main perforating parameter and their influence on skin effect and perforating jobs efficiency.
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Abstract. In this study, high strength steel plates made of 30PM steel were subjected to 7.62 Armour Piercing projectiles at the ordnance velocity. Several experiments differing considerably in conditions of interaction between projectiles and plates were performed. Selected parameters were measured before, during, and after ballistic tests, and both projectile and plate were subjected to detailed examination. It is foreseen to use the obtained results in two ways. Protection performance of steel plates will be determined and experimental data will be used as a reference for analyzing various models and numerical techniques, accessible in commercially available hydrocodes. The authors present the methodology, the experimental set-up configuration, and the results of laboratory experiments.
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