ilk mesajım buydu YAZI YAZDIN AMA %6 HUMAN DİYOR B...

ilk mesajım buydu YAZI YAZDIN AMA %6 HUMAN DİYOR BUNU DÜZENLEMEMİZ LAZIM .
İLLA SIRALAMAYA TAKILMA TEKRARLAMA OLMASIN SIRAYI DEĞİŞTİREBİLİRSİN
BİRAZ DAHA İNSANIN YAZDIĞI BELLİ OLAN KALIPLAR KULLAN SO WE ASSUMED FALAN GİBİ EDATLARIDA KULLAN KONULAR ARASINDA BAĞLANTI KUR . :
güzel ama böyle olmaz bu grup projesi . e first things I noticed is that a low pressure drop is very important. böyle bir cümle olmaz . Ai yazdığı belli olmasın diye ilk okul seviyesi bir şey yazma . üniversite raporu bu .

bana literature survey için yazı lazım . bu slaytlar için detaylı literature survey lazım referansları ile beraber . ama hoca bunu turnitinte taratıcak o yüzden ben yazmışım gibi gözükmesi lazım . mesela ben basit kelimeler kullanıyorum . üniversite seviyesinde olsun ama chatgpt yazmış gibi gözükmesin . biraz daha basit bir dil kullan ama ilk okul seviyeside olmasın yani üniversite dersi sonuç olarak bu . ingilizce yaz . ŞİMDİ bunla başla :
işine yarayabilecek referanslar

Evet, bu sonuçlara göre Winston AI Detection Tool metni %6 insan yazımı / %94 yapay zekâ üretimi olarak değerlendirmiş. Bu, sistemin metnin büyük oranda bir yapay zekâ aracıyla üretildiğine yüksek olasılık verdiğini gösteriyor.
ÖNCEKİ SENİN MESAJIN
İşte raporun kısa analiz ve açıklaması:

🔴 Human Score: %6
Bu oran çok düşük. Winston, bu metnin neredeyse tamamının yapay zekâ tarafından yazıldığını düşünüyor.

Uyarıda da:

"It is highly probable that an AI text generation tool was used."
yazıyor.

📉 Readability Score: 37/100
Bu, metnin okunabilirliğinin düşük olduğunu, fazla akademik, karmaşık ya da teknik olduğunu gösteriyor.

ABD üniversite seviyesi düzeyinde zor bir metin olduğu belirtilmiş.

AI araçları bazen çok “resmî ve yapay” yazdığı için bu puanlar düşebilir.

⚠️ Plagiarism bölümü kilitli, ancak önemli değil çünkü bu uyarı sadece AI tespitiyle ilgili.
🛠️ Ne Yapabilirsin? (Çözüm Önerileri):
Eğer metni sen yazdıysan ama Winston bunu yanlışlıkla AI olarak algıladıysa, şu değişiklikleri yaparak skorunu büyük oranda artırabilirsin:

✅ 1. Karmaşık Cümleleri Basitleştir
Uzun cümleleri böl.

Daha sade, doğal ve konuşma diline yakın ifadeler kullan.

Örnek (AI gibi):

The use of laminar flow ensures a steady and predictable fluid behavior within the system.

İnsan gibi yeniden yaz:

When we use laminar flow, the fluid moves smoothly and predictably. This makes the system easier to control.

✅ 2. Kişisel Gözlem ve Yorum Ekle
AI metinleri genelde kişisel görüş içermez. Metnine şunları serpiştirebilirsin:

"In practice, I observed that..."

"This method is often used because it's simple and reliable..."

"According to my research..."

✅ 3. Çok Tekrarlanan Kalıpları Sil/Değiştir
“Literature Survey:” gibi tekrar eden başlık ve yapılar, AI izi bırakır. Daha doğal başlıklar kullan:

“Past Studies on Heat Recovery”

“What the Research Says About Laminar Flow”

🎯 Alternatif: Dilersen Metni Yeniden Yazayım
Eğer istersen, AI skoru düşecek şekilde metni yeniden yazabilirim. Şu yollarla:

Daha insani dil,

Kısa ve anlaşılır cümleler,

Kişisel dokunuşlar (yorumlar, geçişler, örnekler),

Tekrarların kaldırılması. metin : Design Considerations in Blood Heat Exchangers
Blood heat exchangers are essential devices in many medical procedures, especially during open-heart surgeries. These devices help control the temperature of the blood by cooling or warming it as needed. Over time, many improvements have been made to make these devices safer, more efficient, and easier to use. Below are the key design features that are important according to the literature.

1. Low Pressure Drop
   A low pressure drop inside the heat exchanger is important to prevent hemolysis, which is the damage or destruction of red blood cells. If the pressure is too high, the blood cells can break apart, which can be dangerous for the patient. Research has shown that smooth and laminar flow is the best for reducing stress on the blood (Acta Mechanica Slovaca, 2020). In the past, simple models didn’t consider blood as a complex fluid, but newer computational fluid dynamics (CFD) studies in the 2010s started including non-Newtonian properties of blood, which helped in reducing hemolysis during heat exchange (Pennes, 1948; Acta Mechanica Slovaca, 2020).
2. Controlled Temperature Range
   During surgeries, especially heart surgeries, the patient’s body temperature is often lowered to around 27 °C to protect organs and slow down body functions. However, this must be done gradually and precisely to avoid thermal shock, which can harm the patient. Early systems used external methods like ice packs, but they were slow and not precise (Pennes, 1948). In 1957, the Brown-Harrison heat exchanger allowed controlled and quick temperature adjustment (ASME, 1980). Modern devices now use advanced materials and sensors to control blood temperature with high precision (Vasulin & Oslejsek, 1965).
3. Biocompatible Materials
   All materials used inside the heat exchanger must be biocompatible, meaning they should not cause any reaction in the body. The surface needs to be smooth, non-reactive, and easy to sterilize, so that it does not cause blood clots or inflammation. Standards like ISO 10993 and ASTM F748-12 ensure that the materials used are safe and approved for medical use. If the material is not biocompatible, it can lead to serious complications like clotting or immune responses (ISO 10993; ASTM F748-12).
4. Easy to Clean
   Hygiene is extremely important in medical tools, especially those that come into contact with blood. Gasketed plate heat exchangers are often preferred because they can be easily opened, cleaned, and reassembled. This is important to ensure there is no cross-contamination between surgeries. It also helps reduce the time needed for cleaning and preparation, making surgical procedures more efficient (Acta Mechanica Slovaca, 2020).
5. Compact and Modular Design
   Today’s medical environments, especially surgical rooms, require devices that are compact and easy to move. Heat exchangers are now designed to be modular, meaning they can be adapted or replaced part by part. This makes them easier to integrate into existing equipment. Some newer designs are also portable or even single-use, especially in emergency or battlefield conditions. These features help in saving space and improving flexibility in surgery (Ecker & Hertzman, 1939; ASME, 1980).
   Engineering Limits in Blood Heat Exchangers
   In the design of blood heat exchangers, engineering constraints are critical to ensure both patient safety and device performance. These limits define the safe operating conditions under which the device can function without causing damage to blood components or risking system failure. Several key parameters—such as pressure drop, flow rate, operating temperature, and heat transfer coefficient—must be considered during the design and testing stages.
6. Maximum Pressure Drop
   One of the most important safety factors is the maximum pressure drop on the blood side. According to the literature, this value should stay below 500 pascals (Pa) to prevent hemolysis, which occurs when red blood cells are exposed to high mechanical stress (Acta Mechanica Slovaca, 2020). If the pressure drop is too high, it can cause shear forces that damage blood cells, leading to serious complications during surgery. For this reason, modern heat exchangers are carefully designed to keep the pressure within safe limits by using laminar flow channels and smooth surfaces (Pennes, 1948).
7. Flow Rate
   The blood flow rate through the exchanger is another crucial parameter. Under normal conditions, the human heart pumps about 5 liters of blood per minute (Ganong, 2016). However, during cardiac surgery or while using a heart-lung machine, the flow is usually lower to allow better control and reduce metabolic demand. In practical designs, especially for experimental or project-based systems, the accepted flow rate range is around 1 to 5 L/min. This range covers both reduced clinical flow during surgery and upper limits closer to physiological conditions. It also gives enough flexibility for testing and safety (Bassi et al., 2019).
8. Material Thermal Rating
   Materials used in blood heat exchangers must be rated for continuous use at body temperature, which is about 37 °C. This is important not only for safety but also for long-term durability and performance. If the material is not thermally stable, it may degrade, leach chemicals into the blood, or lose its structural integrity. Materials like medical-grade stainless steel, polycarbonate, and certain polymers are commonly used because they are biocompatible, chemically resistant, and thermally stable at this temperature (ISO 10993; ASTM F748-12).
9. Overall Heat Transfer Coefficient
   The overall heat transfer coefficient (U-value) describes how effectively heat can move through the exchanger surfaces between the blood and the cooling or warming fluid, typically water. For plate-type blood heat exchangers, typical values range from 800 to 1200 W/m²·K (Zhang et al., 2020). A higher U-value means faster heat exchange, which is important to meet clinical temperature targets within a short time. This is especially critical during the induction or reversal of hypothermia in heart surgery.

---

Why Low Pressure Drop Is Critical in Blood Heat Exchangers
Maintaining a low pressure drop in blood heat exchangers is not just a design preference, but a clinical necessity. While earlier research emphasized minimizing hemolysis due to mechanical stress, newer studies have also explored how fluid dynamics directly impact blood compatibility, system efficiency, and even long-term patient outcomes.
Red blood cells (RBCs) are known to be sensitive to shear forces, which increase when blood flows through narrow or uneven channels at high velocity or under turbulent conditions. Studies show that hemolysis begins to increase rapidly when the shear stress exceeds 150 Pa, especially during longer perfusion durations (Paul et al., 2015). Therefore, turbulence and rapid pressure changes, especially in areas like sharp corners or poorly designed inlets/outlets, should be strictly avoided.
Using laminar flow patterns inside the exchanger is preferred because it creates a smooth and steady flow, reducing direct mechanical trauma to blood cells. Moreover, a lower pressure drop also reduces the load on the perfusion pump, allowing smaller and more energy-efficient systems to be used—an advantage in both clinical and portable settings (Kim et al., 2021).
Another important point is that pressure drop is closely linked to residence time. If blood flows too slowly due to high resistance, it may be exposed longer to heat exchanger surfaces, which increases the risk of protein denaturation or cell membrane degradation. This is especially critical in pediatric surgeries, where smaller volumes and delicate physiology make patients more vulnerable to blood trauma (Jang & Lee, 2018).
Recent computational models have helped researchers simulate and visualize how different channel geometries and surface textures affect pressure drop and flow uniformity. Microchannel heat exchangers with optimized geometry have been shown to offer low pressure drop while maintaining efficient heat transfer (Chen et al., 2022). These innovations aim to balance both thermal performance and hemocompatibility.

---

Design Strategies to Reduce Pressure Drop in Blood Heat Exchangers
Minimizing pressure drop in blood heat exchangers is essential for both protecting blood components and improving device efficiency. To achieve this, engineers apply various fluid dynamics principles and biomedical constraints in the design phase. Each component—from the channel geometry to the surface coating—can have a measurable impact on pressure drop and overall flow behavior.

1. Wide Flow Channels and Low Velocities
   Using wide flow channels is one of the most effective ways to reduce flow resistance. Wider channels help to decrease velocity and maintain laminar flow, especially important for blood, which is a non-Newtonian fluid. Research shows that blood behaves more sensitively to shear stress at higher velocities, especially in narrow gaps (Yeleswarapu, 1996). Lower flow speed also contributes to reduced mechanical stress on red blood cells.
2. Avoiding Sharp Bends and Multi-Pass Layouts
   Channel geometry plays a key role in pressure management. Designs that include sharp turns, sudden contractions, or multi-pass configurations can lead to localized turbulence and higher pressure drops. Smooth, straight flow paths are preferred. In one study, redesigning a multi-pass blood heat exchanger into a single-pass configuration led to a 25% reduction in pressure drop without losing thermal performance (Liu et al., 2020).
3. Rounded Ports and Smooth Transitions
   Port design also affects the pressure profile at the entry and exit points. Sharp port angles or abrupt transitions can cause entry losses, which are pressure losses due to flow separation or recirculation zones. Instead, rounded or bell-shaped ports help create a smoother inflow, minimizing resistance and flow disturbances (Koo et al., 2017).
4. Plate Optimization: Number and Size
   The number and size of plates used in a plate-type heat exchanger must be optimized. More plates increase surface area (which is good for heat transfer), but can also raise flow resistance if spacing is too tight. Researchers recommend using fewer but wider plates when pressure drop is a concern, or adjusting the chevron angle to control turbulence without increasing shear forces (Müller-Steinhagen, 2003).
5. Smooth and Coated Surfaces
   The surface texture and material of the flow channels influence frictional losses. Surfaces with micro-roughness or imperfections can disturb laminar flow, increasing drag and shear. Many modern designs use hydrophilic polymer coatings or Teflon-like materials to ensure low surface roughness and good blood compatibility (ISO 10993; Krajewski et al., 2019). These coatings also help reduce the risk of clotting and protein adhesion, contributing to overall biocompatibility.

---

The thermal and physical properties of water and blood were collected from established literature sources to guide realistic modeling of heat exchanger performance. Blood, compared to water, has higher viscosity and density, which significantly affects pressure drop and heat transfer behavior under typical surgical flow rates (approx. 4 L/min). These values help ensure that design simulations and calculations reflect realistic clinical conditions.
Modeling Blood as a Newtonian Fluid
Blood is inherently a non-Newtonian fluid, meaning its viscosity is not constant—it changes with the shear rate. Specifically, blood exhibits shear-thinning behavior, where viscosity decreases as flow rate increases (Yilmaz & Gundogdu, 2008). However, under moderate to high flow rates, like those used in cardiac surgeries (3–5 L/min), the viscosity of blood tends to stabilize.
This observation allows researchers and engineers to treat blood as a Newtonian fluid for simplicity, especially when using standard fluid mechanics equations in the design and analysis of biomedical heat exchangers. Several studies have validated this approximation as accurate enough for most engineering-level simulations and CFD models (Sochi, 2010; Kakaç et al., 2012).
By applying the Newtonian model, the design process becomes more straightforward, and analytical solutions can be obtained without losing significant accuracy in pressure drop or heat transfer predictions.
Heparin-Based Silicone Coatings for Biocompatibility
In blood-contacting devices like heat exchangers, surface biocompatibility is critical. If the inner surfaces are not properly treated, blood can react by forming clots, activating immune responses, or leaving behind protein/cell deposits, which reduce device performance and increase patient risk.
To prevent this, many biomedical devices use heparin-based silicone coatings. Heparin is an anticoagulant, and when bonded to a hydrophilic silicone layer, it creates a surface that resists clot formation, cell adhesion, and protein fouling (Ratner et al., 2004). These coatings are also smooth and soft, which further reduces shear damage to blood components.
Such coatings are compatible with common device materials like stainless steel, polymers, and silicone, and they retain their properties under repeated sterilization cycles (Jaffer et al., 2015). They also support long-term contact with blood, which is essential during extended surgical procedures or in extracorporeal circuits.
By improving surface biocompatibility, these coatings help maintain a clean and safe environment for blood flow, and they reduce the need for aggressive anticoagulant drug therapy during surgery.

Fouling Resistance (Rf) on Blood Side
Fouling refers to the buildup of cells, proteins, or particles on the heat exchanger surfaces, which reduces heat transfer efficiency. In blood heat exchangers, fouling can also lead to blockages, clotting, or infection risk.
However, in sterile medical environments—especially when using heparin-based coatings and maintaining closed-loop circuits—the fouling on the blood side is usually very low. The laminar flow conditions commonly used in surgery also help by minimizing particle deposition and reducing contact time with surfaces.
According to literature, the typical fouling resistance on the blood side is between 10⁻⁴ and 10⁻⁶ m²·K/W, depending on flow rate, surface material, and coating (Noble & Bergles, 1972). Because this value is so small, many engineering models assume Rf ≈ 0 for simplicity without causing significant error in heat transfer calculations (Kakaç et al., 2012).
This assumption is especially valid when the device is cleaned properly and used only during a single surgical session, which is common in clinical setups.
Constant Viscosity Assumption
In most engineering models, blood viscosity is assumed constant (≈ 0.00045 kg/m·s) under surgical conditions. This helps apply standard equations like Reynolds number and Nusselt correlations for heat transfer and pressure drop calculations.
Although blood is non-Newtonian, at medium-to-high flow rates (e.g., 3–5 L/min), its viscosity remains stable, making the assumption acceptable. This is supported by studies such as Sochi (2010) and Yilmaz & Gundogdu (2008).