Guidelines and benchmarking of the internal combustion engine components for enhacement of NVH performance

Osim manje potrošnje goriva i velike snage, udobnost u vožnji vrlo je važan zahtjev kod kupnje vozila. Budući da je motor s unutarnjim izgaranjem jedan od glavnih izvora buke i vibracija u vozilima, analiza buke i vibracija predstavlja velik izazov u razvoju motora s unutarnjim izgaranjem. Cilj ovog rada je odrediti odgovarajuću metodu koja bi omogućila predviđanje vibracija pojedinih komponenata motora s unutarnjim izgaranjem na početku razvoja prije nego što je poznata konstrukcija cijelog motora. Time bi se smanjili troškovi i vrijeme potrebno za razvoj motora s unutarnjim izgaranjem. Analizirana su tri prednabijena redna trocilindarska Otto motora. Pojedini dijelovi motora (usisna grana, uljno korito i poklopac glave motora) analizirani su u trećinsko-oktavnom pojasu od 800 Hz do 3150 Hz (frekvencijsko područje od 708 Hz do 3548 Hz). Prvo je potrebno definirati odgovarajuće rubne uvjete koji bi zamijenili utjecaj opterećenja koje se prenosi iz bloka motora preko vijčanog spoja na određenu komponentu motora. Rubni uvjeti su definirani u obliku ubrzanja. Nakon toga, različiti tipovi krivulja ubrzanja primjenjuju se u čvorovima na mjestima vijčanog spoja promatrane komponente s ostatkom strukture. Na kraju, rezultati su uspoređeni na temelju raspodjele vibracija po površini strukture i ovisno o tome koliko pojedina komponenta pridonosi ukupnim vibracijama motora s unutarnjim izgaranjem.Lower fuel consumption and high power, together with the increased driving comfort, represent some of the most important customer demands. Since internal combustion engine represents one of the biggest contributors to the overall noise and vibration levels, a special attention should be given to the NVH (noise, vibration, harshness) analysis. The objective of this study is to define a method for predicting the NVH performance of the engine components at early stages of engine development before they are coupled to the full engine assembly. As a result, the whole development process would be less time and money consuming. The study is conducted for three gasoline turbocharged inline 3-cylinder engines. Engine components (intake manifold, oil pan and cam cover) are analyzed in mid and high frequency domain for 3rd octave band 800 Hz up to 3rd octave band 3150 Hz (from 708 Hz to 3548 Hz). The first step is to define the adequate boundary conditions that will replace the impact of the forces generated in the engine block and transmitted through the bolts to the observed component. Boundary conditions are defined in the form of enforced motions (accelerations). After that, different types of acceleration curves are applied as excitations at the bolt locations in the forced frequency response analysis. Finally, structure response is evaluated in 3rd octave bands based on the distribution of the surface velocities and the contribution of the observed component to the overall noise radiation level

Advancing Translational Space Research Through Biospecimen Sharing: Amplifying the Impact of Ground-Based Studies

Biospecimen Sharing Programs (BSPs) have been organized by NASA Ames Research Center since the 1960s with the goal of maximizing utilization and scientific return from rare, complex and costly spaceflight experiments. BSPs involve acquiring otherwise unused biological specimens from primary space research experiments for distribution to secondary experiments. Here we describe a collaboration leveraging Ames expertise in biospecimen sharing to magnify the scientific impact of research informing astronaut health funded by the NASA Human Research Program (HRP) Human Health Countermeasures (HHC) Element. The concept expands biospecimen sharing to one-off ground-based studies utilizing analogue space platforms (e.g., Hind limb Unloading (HLU), Artificial Gravity) for rodent experiments, thereby significantly broadening the range of research opportunities with translational relevance for protecting human health in space and on Earth. In this presentation, we will report on biospecimens currently being acquired from HHC Award Head-Down Tilt as a Model for Intracranial and Intraocular Pressures, and Retinal Changes during Spaceflight, and their availability. The BSP add-on to the project described herein has already yielded for HHC-funded investigators more than 4,700 additional tissues that would otherwise have been discarded as waste, with additional tissues available for analysis. Young (3-mo old) male and female rats and Older (9-mo old) male rats are being exposed to HLU for either 7, 14, 28, or 90 days. Additional groups are exposed to 90 days of unloading followed by either 7, 14, 28 days or 90 days of recovery (normal loading). Comparisons are made with non-suspended controls. Unused tissues are: Skin, Lungs, Thymus, Adrenals, Kidneys, Spleen, Hindlimb Muscles (Soleus, Extensor Digitorum Longus, Tibialis Anterior, Plantaris Gastrocnemius), Fat Pads, Reproductive Organs, and Intestines. Tissues are harvested, weighed, preserved then archived (with metadata) using a sample tracking system (CryoTrack). Preservation techniques include snap-freezing and RNALatersnap-freezing. Specimens were weighed at the time of dissection, and organ mass: body mass ratios analyzed to determine unloading effects across conditions and durations. The results corroborate previously reported effects of short-term exposure to microgravity or unloading exposure on various organs, and provide new insights into adaptation to long-duration unloading relevant to sustained spaceflight exposures on ISS. Supported by the Human Research Program (HRP) Human Health Countermeasures (HHC) Element and NASA Grant NNX13AD94G (CAF)

Menținerea viabilității organelor preconizate pentru transplant prin aplicarea metodelor ex-vivo de recondiționare sau tratament

Background: Advanced organ failure is considered the terminal stage of the disease, in which curative options are limited to targeted treatment of the organ by ex-vivo approach. This method can solve the global problem of organs deficiency. Objective of the study. Presenting the benefits of the ex-vivo approach for organs with injured function, in patients with absolute indications for organ transplantation. Material and Methods. It has been studied the available articles on PubMed and Medscape, published between 2000-2021. Methods of organ prelevation, preparation for extracorporeal circulation, the maintenance of the tissue viability in ex-vivo conditions, the application of targeted treatment in severe infections/tumors and tissue revitalization post-injury, have been analyzed. Results: The benefit of the ex-vivo approach to any organ is the extended therapeutic range compared to the in-vivo approach. Ex-vivo organs reconditioning before transplantation can be performed by several methods. One of them would be targeted drug treatment with high therapeutic doses, which in conditions with standard in-vivo doses have not proven to be effective. Surgical removal of hard-to-reach tumors, their irradiation with high doses of radiation and/or chemotherapy followed by autotransplantation, can be performed too. Another usage of this method would be the revitalization of the lungs that do not meet the mandatory criteria for transplantation, with STEEN solution. Conclusions: The application of ex-vivo treatment in the case of patients suffering from terminal stage diseases, will allow them a more rapid access to a viable and suitable organ, which will increase their life expectancy.Introducere: Insuficiența organică avansată reprezintă etapa terminală a bolii, în care opțiunile curative se limitează la tratamentul țintit asupra organului abordat ex-vivo. Aceasta poate rezolvă problema mondială a deficitului de organe. Scopul lucrării: Evidențierea beneficiilor în abordarea ex-vivo a organelor cu funcție compromisă, la pacienții cu indicații absolute pentru transplant. Material și Metode: S-au revizuit articolele disponibile pe PubMed, Medscape publicate între 2000-2021. S-au analizat metodele de prelevare a organelor, pregătirea lor pentru circulația extracorporală, menținerea viabilității țesuturilor în condiții ex-vivo, aplicarea tratamentului focalizat în condiții de infecții severe/tumori și revitalizarea țesuturilor după traumatism. Rezultate: Beneficiul clinic al abordării ex-vivo a oricărui organ constă în diapazonul terapeutic extins în comparație cu abordarea in-vivo. Recondiționarea organului ex-vivo pretransplant, poate fi efectuată prin mai multe metode: cura medicamentoasă cu doze terapeutice mari vis-à-vis dozelor standarde in-vivo ineficiente; înlăturarea chirurgicală a tumorilor greu accesibile urmată de autotransplantare; iradierea tumorilor cu doze mari de radiație ionizantă sau/ și aplicarea chimioterapiei cu autotransplantarea ulterioară. Încă o întrebuințare ar fi, revitalizarea plămânilor necorespunzători criteriilor obligatorii pentru transplantare, cu soluție STEEN. Concluzii: Aplicarea tratamentului ex-vivo în cazul pacienților care suferă de boli în stadiul terminal, permite accesul bolnavilor la un organ viabil la momentul oportun, fapt ce crește speranța de viață a acestora

THE MAINTENANCE OF THE ORGANS VIABILITY FOR TRANSPLANTATION BY APPLYING EX-VIVO METHODS OF RECONDITIONING OR TREATMENT

Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”, Chişinău, Republica MoldovaIntroducere: Insuficiența organică avansată reprezintă etapa terminală a bolii, în care opțiunile curative se limitează la tratamentul țintit asupra organului abordat ex-vivo. Aceasta poate rezolvă problema mondială a deficitului de organe. Scopul lucrării: Evidențierea beneficiilor în abordarea ex-vivo a organelor cu funcție compromisă, la pacienții cu indicații absolute pentru transplant. Material și Metode: S-au revizuit articolele disponibile pe PubMed, Medscape publicate între 2000-2021. S-au analizat metodele de prelevare a organelor, pregătirea lor pentru circulația extracorporală, menținerea viabilității țesuturilor în condiții ex-vivo, aplicarea tratamentului focalizat în condiții de infecții severe/tumori și revitalizarea țesuturilor după traumatism. Rezultate: Beneficiul clinic al abordării ex-vivo a oricărui organ constă în diapazonul terapeutic extins în comparație cu abordarea in-vivo . Recondiționarea organului ex-vivo pretransplant, poate fi efectuată prin mai multe metode: cura medicamentoasă cu doze terapeutice mari vis-à-vis dozelor standarde in-vivo ineficiente; înlăturarea chirurgicală a tumorilor greu accesibile urmată de autotransplantare; iradierea tumorilor cu doze mari de radiație ionizantă sau/ și aplicarea chimioterapiei cu autotransplantarea ulterioară. Încă o întrebuințare ar fi, revitalizarea plămânilor necorespunzători criteriilor obligatorii pentru transplantare, cu soluție STEEN. Concluzii: Aplicarea tratamentului ex-vivo în cazul pacienților care suferă de boli în stadiul terminal, permite accesul bolnavilor la un organ viabil la momentul oportun, fapt ce crește speranța de viață a acestora.Background: Advanced organ failure is considered the terminal stage of the disease, in which curative options are limited to targeted treatment of the organ by ex-vivo approach. This method can solve the global problem of organs deficiency. Objective of the study. Presenting the benefits of the ex-vivo approach for organs with injured function, in patients with absolute indications for organ transplantation. Material and Methods. It has been studied the available articles on PubMed and Medscape, published between 2000-2021. Methods of organ prelevation, preparation for extracorporeal circulation, the maintenance of the tissue viability in ex-vivo conditions, the application of targeted treatment in severe infections/tumors and tissue revitalization post-injury, have been analyzed. Results: The benefit of the ex-vivo approach to any organ is the extended therapeutic range compared to the in-vivo approach. Ex-vivo organs reconditioning before transplantation can be performed by several methods. One of them would be targeted drug treatment with high therapeutic doses, which in conditions with standard in-vivo doses have not proven to be effective. Surgical removal of hard-to-reach tumors, their irradiation with high doses of radiation and/or chemotherapy followed by autotransplantation, can be performed too. Another usage of this method would be the revitalization of the lungs that do not meet the mandatory criteria for transplantation, with STEEN solution. Conclusions: The application of ex-vivo treatment in the case of patients suffering from terminal stage diseases, will allow them a more rapid access to a viable and suitable organ, which will increase their life expectancy

Prijenosnički modul za elektromotor

Potrebno je proračunati i konstruirati planetarni prijenosnik za radni stroj snage P=10 kW i brzine vrtnje n=250 min-1. Obzirom na potrebnu izlaznu snagu i gubitke prijenosnika, proračunava se potrebna snaga elektromotora te se odabire elektromotor tvrtke Končar. Daljnji proračun sastoji se od proračuna zupčanika prema normi ISO 6336, provjere naprezanja ulaznog i izlaznog vratila, osovine planetarnog zupčanika i ručice te odabira ležajeva. Proračun vratila, osovine, ručice i ležajeva proveden uz pretpostavku da se snaga prenosi samo preko dva (od ukupno tri) planetarna zupčanika. Kod konstruiranja prijenosnika potrebno je obratiti pažnju na radijalne dimenzije prijenosnika koje moraju biti u skladu s radijalnim dimenzijama elektromotora. Budući da je odlučeno da se centralni zupčanik s unutarnjim ozubljenjem izrađuje u jednom komadu s kućištem, dimenzije tog zupčanika izravno utječu na radijalne dimenzije prijenosnika. Dimenzije zupčanika (u ovom slučaju i dimenzije prijenosnika) mijenjaju se ovisno o broju zubi i modulu zupčanika. Pravilnom kombinacijom ta dva parametra postiže se usklađenost dimenzija. Nadalje, prijenosnik se na elektromotor i radni stroj mora montirati prirubnicom. U ovom slučaju odabrane su jednake dimenzije obiju prirubnica

Smjernice za usporedbu i procjenu elemenata motora s unutarnjim izgaranjem u svrhu poboljšanja buke i vibracija

Osim manje potrošnje goriva i velike snage, udobnost u vožnji vrlo je važan zahtjev kod kupnje vozila. Budući da je motor s unutarnjim izgaranjem jedan od glavnih izvora buke i vibracija u vozilima, analiza buke i vibracija predstavlja velik izazov u razvoju motora s unutarnjim izgaranjem. Cilj ovog rada je odrediti odgovarajuću metodu koja bi omogućila predviđanje vibracija pojedinih komponenata motora s unutarnjim izgaranjem na početku razvoja prije nego što je poznata konstrukcija cijelog motora. Time bi se smanjili troškovi i vrijeme potrebno za razvoj motora s unutarnjim izgaranjem. Analizirana su tri prednabijena redna trocilindarska Otto motora. Pojedini dijelovi motora (usisna grana, uljno korito i poklopac glave motora) analizirani su u trećinsko-oktavnom pojasu od 800 Hz do 3150 Hz (frekvencijsko područje od 708 Hz do 3548 Hz). Prvo je potrebno definirati odgovarajuće rubne uvjete koji bi zamijenili utjecaj opterećenja koje se prenosi iz bloka motora preko vijčanog spoja na određenu komponentu motora. Rubni uvjeti su definirani u obliku ubrzanja. Nakon toga, različiti tipovi krivulja ubrzanja primjenjuju se u čvorovima na mjestima vijčanog spoja promatrane komponente s ostatkom strukture. Na kraju, rezultati su uspoređeni na temelju raspodjele vibracija po površini strukture i ovisno o tome koliko pojedina komponenta pridonosi ukupnim vibracijama motora s unutarnjim izgaranjem

Contemporary methods of intraoperative navigation in brain tumour surgery

Introduction. Contemporary methods of intraoperative navigation in brain tumour surgery are investigations that allow the neurosurgeon to obtain information about the lesion, the distance to it, and its relationship with adjacent structures. Aim of study. To provide information about the advantages and disadvantages of the methods that are currently used in intraoperative neurosurgery. Methods and materials. Galearschi V 2012 Metode Contemporane de reperaj in tumorile cerebrale (46- 52) Pubmed.ncbi.nlm.nih. Results. Computed tomography is a method that has the advantage of a higher anatomical resolution than USG, better visualisation of bone and calcified structures and faster imaging time than the MRI and is suitable to visualise bone destruction, hyperostosis, erosion or penetration. A disadvantage would be that the images obtained are only in the axial incidence, plus the images of the posterior fossa are limited as a result of bone artefacts. This method poses an increased risk of X-ray exposure and is only practised in specialised clinics. Ultrasonography as a method has gained confidence primarily due to its lack of invasiveness, plus it has a higher affinity for cystic formations than CT and MRI, it provides real-time data on intraoperative dislocation of brain anatomical structures and as a price-profit it is a cost-effective method. But some aspects may be disadvantageous because USG may fail to differentiate low-grade astrocytomas, plus it would require acoustic coupling, and imaging is limited by limited lateral resolution. MRI is considered a top investigation in neurosurgical screening because it has a number of advantages, such as early detection of brain tumours, allows a clearer picture of neuro-anatomical components, a very good view in case of cerebral edema, allows highlighting tumour boundaries, and the differentiation of the vascular structures from the bone artefacts, it allows to obtain images of very good resolution in a very short period of time. A major disadvantage would be that the availability of the use of this method is low, and its use is allowed only in specially equipped centres. Conclusion. A conclusion based on these methods notes that neuronavigation development is accelerating, knowledge of these techniques is very important and necessary but the best, accessible and useful methods remain the eyes and knowledges of the neurosurgeon

Gout in women

Introduction. The incidence of gout has doubled in women over the past 20 years, according to the Rochester Epidemiological Project. Given the important role of estrogen in serum uric acid concentrations as well as the substantial difference in the incidence of gout between the sexes and probably in uric acid metabolism. Case presentation. The patient CM, 65 years old, was hospitalised in the Nephrology Department IMSP SCR "Timofei Moşneaga" accusing: low back pain, bilateral, permanent arthralgias in the joints of the lower limbs, accentuated at the knees, permanent pain, increasing in intensity to physical exertion; morning stiffness; precordial pain, constrictive type; mild dyspnea on exertion; marked asthenia; fatigue; dizziness. Precordial drugs twice a month. He went to the Institute of Cardiology, the diagnosis of rheumatic valvulopathy was established: mitral regurgitation. Hypertension, grade III, very high additional risk. Severe bradycardia, FCC 30-35 b/m, in 2009 the patient was implanted with electrocardiostimulator. After the age of 50, arthralgias in the knee joints intensified. In 2010, the diagnosis was established: Secondary gout, mixed variant, chronic evolution. Left kidney nephrosclerosis. Right renal artery stenosis. In 2019, clinical diagnosis was established: Secondary gout, mixed variant, chronic gout, with damage to the joints of the lower limbs, in association with osteoarthritis, polyosteoarthritis, bilateral gonarthrosis, st.R.II-III. Mixed osteoporosis. Chronic bilateral pyelonephritis, recurrent evolution, incomplete remission. Uric nephropathy. Left kidney nephrosclerosis. Right renal artery stenosis. Additional right renal artery. BCR IV. Mixed grade II anemia. Rheumatic valvulopathy: wide mitral stenosis of the mitral valve. V Mtr. Insufficiency VAo. gr.II. Insufficiency VTr gr.II. Calcined gr.IV in the cusps VAo gr.II. Moderate pulmonary hypertension (50mmHg). FE 63%. Hypertension gr.II-III, very high additional risk. ICC II-III (NYHA). Chronic hepatitis of viral etiology. Mixed chronic discirculatory encephalopathy grade II-III. Discussion. The main impediment in the diagnosis of gout in women, however, is the rarity of this disease in females. In the postmenopausal period, most patients have a non-specific clinical picture, there is no classic acute access to gout, which is why it is required to make a differential diagnosis with a series of diseases starting in the postmenopausal period. Conclusion. We wanted to highlight once again the increased incidence of gout in the postmenopausal period, especially in women with earlier onset of menopause as in the case of our patient. The patient chronically uses diuretics, which still causes hyperuricemia

Arterial hypertension, cardiovascular remodeling and plasma level of osteopontin in patients with end-stage kidney disease on hemodialysis

Aim. Large population-based studies acknowledge that patients with chronic kidney disease have a high risk of cardiovascular diseases regardless of etiology, especially in its late stages. The aim of this study was to investigate the features of arterial hypertension, cardiovascular remodeling and plasma level of osteopontin in dynamics of candesartan therapy, as well as to identify the relationships between studied parameters in patients with chronic kidney disease treated by hemodialysis. Methods and results. 50 patients were performed ambulatory blood pressure monitoring, the plasma level of osteopontin was determined by ELISA method, standard echocardiography and ultrasonography of common carotid after treatment of candesartan during 12 weeks. Conclusion. The results indicate that the use of candesartan cilexetil in hemodialysis populations promotes regression of left ventricular hypertrophy and vascular remodeling indices, has antihypertensive effect

Cardiovascular aspects and the state of vegetative balance in patients with arterial hypertension associated with dyslipidemia

Objective. The aim of this study was to investigate the effect of dyslipidemia on cerebral and intra-cardiac hemodynamics, heart and blood vessels remodeling and the state of vegetative balance in patients with hypertension. Materials and Methods. 100 patients with stage II arterial hypertension (AH) were examined. Depending on the total cholesterol (TCh) level, all patients were divided into two groups: the group I included 69 patients with AH and hypercholesterolemia (HCE), the group II - 31 patients without HCE. All patients were subjected to the evaluation of DMAР, echocardiography, duplex pulsed-wave Doppler extracranial vessels, heart rate variability (HRV) according to the Holter monitoring of ECG. Results. TCh levels over 5 mmol/L were observed in 69% of patients with AH. Hypertensive patients with HCE and patients with normal level of TCh did not differ from each other in all indicators of "office" blood pressure, LV systolic and diastolic function parameters and pressure in LA. Patients with AH associated with HCE had a significantly larger LA size in systole by 10.8% and diastole by 6.9%, and the thickness of IVS in systole by 13.33%. There was a significant decrease in the maximum linear velocity of blood flow in both CCAs by 11%, in both VAs by 16%, in BA by 12.9%, as well as a reliable decrease in the vascular reactivity index of sensitivity to hypercapnia in BA by 15.1% in the group I. Patients of both groups did not differ in all time and spectral indices of HRV, however, hypertensive patients with HCE had increased activity of the sympathetic nervous system, as demonstrated by the LF/HF index of more than 2 CU. Conclusions. The presence of hypercholesterolemia in patients with AH does not affect significantly the level of blood pressure, but affects the parameters of cardiac remodeling, and also has an effect on the cerebral blood flow and the state of vegetative balance. hypertension; blood pressure; cardiac remodeling; autonomic regulation; dyslipidemi