{"id":3800,"date":"2019-10-08T07:56:19","date_gmt":"2019-10-08T07:56:19","guid":{"rendered":"https:\/\/www.mcctcarbide.com\/?p=3800"},"modified":"2020-05-06T03:05:28","modified_gmt":"2020-05-06T03:05:28","slug":"what-to-know-about-surface-roughness","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/tr\/yuzey-puruzlulugu-hakkinda-bilinmesi-gerekenler\/","title":{"rendered":"Y\u00fczey P\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc hakk\u0131nda bilinmesi gerekenler"},"content":{"rendered":"

\u0130malat sanayinde y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn \u00e7ok \u015fey ifade etti\u011finin bilincindeyiz. Konsept akl\u0131n\u0131za geldi\u011finde, i\u015flenmi\u015f par\u00e7alarda parlak ayna y\u00fczeyi, mat ve mat cila gibi baz\u0131 ortak dokular olmal\u0131d\u0131r. Makroskopik durumda farkl\u0131 y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn somutla\u015ft\u0131\u011f\u0131 \u015feylerdir. <\/strong><\/strong><\/p>

Y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn tan\u0131m\u0131<\/strong><\/strong><\/h2>

Bilindi\u011fi gibi, bir par\u00e7an\u0131n p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc<\/strong>'<\/strong>s y\u00fczeyi, aralar\u0131nda tepe ve bo\u015fluk bulunan bir dizi p\u00fcr\u00fczl\u00fc vadi olarak profillendirilebilir. <\/strong><\/strong><\/p>

Y\u00fczeyi tan\u0131mlayan bir kavram olarak<\/strong>'<\/strong>Mikroskobik yap\u0131, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc asl\u0131nda bu tepeler (veya \u00e7ukurlar, genellikle 1 mm'nin alt\u0131nda) aras\u0131ndaki uzunluk S ve a\u015fa\u011f\u0131daki \u015femada g\u00f6sterilen \u00e7ukurdan tepeye Z derinli\u011fidir.<\/strong><\/strong><\/p>

Genel olarak, de\u011fi\u015fen y\u00fczey ko\u015fullar\u0131n\u0131 S aral\u0131\u011f\u0131na g\u00f6re ay\u0131rt ederiz.<\/p>

S\uff1c1mm, p\u00fcr\u00fcz, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc olarak kabul edilir,<\/p>

1\u2264S\u226410mm, dalgal\u0131l\u0131k olarak kabul edilir,<\/p>

S\uff1e10mm, geometrik e\u015fitsizlik olarak adland\u0131r\u0131l\u0131r.  <\/p>

\"\"<\/figure>

3 standart ve kar\u015f\u0131la\u015ft\u0131rma tablosu<\/strong><\/strong><\/h2>

\u00c7in'de, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fc \u00f6l\u00e7en standartlar, Ra konturunun ortalama aritmetik sapmas\u0131, ortalama p\u00fcr\u00fczl\u00fcl\u00fck y\u00fcksekli\u011fi Rz ve vadinin maksimum derinli\u011fi Ry olan 3 \u0130ndeks (birim:mm) ile \u00f6l\u00e7\u00fcl\u00fcr.<\/p>

Ger\u00e7ek \u00fcretim faaliyetlerinin \u00e7o\u011funda Ra \u00e7o\u011funlukla uygulan\u0131r. Japonya'da Ry \u00e7o\u011funlukla kullan\u0131l\u0131rken, R olarak an\u0131l\u0131rmaksimum<\/sub>. Avrupa b\u00f6lgesindeki insanlar VDI 3400 kullan\u0131yor. A\u015fa\u011f\u0131da g\u00f6sterilen 3 standard\u0131n bir kar\u015f\u0131la\u015ft\u0131rma tablosunu yapt\u0131k, <\/p>

\"\"<\/figure>

Diyagram 2. Ra, R aras\u0131ndaki kar\u015f\u0131la\u015ft\u0131rma<\/strong>maksimum<\/sub><\/strong><\/sub><\/strong>, ve VDI3400.<\/strong><\/strong><\/p>

Y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn olu\u015fum fakt\u00f6rleri<\/strong><\/strong><\/h2>

Y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc genellikle i\u015fleme y\u00f6ntemleri ve tak\u0131m ile par\u00e7a y\u00fczeyi aras\u0131ndaki s\u00fcrt\u00fcnme, tala\u015flar ayr\u0131ld\u0131\u011f\u0131nda y\u00fczey metalinin plastik deformasyonu, proses sisteminde y\u00fcksek frekansl\u0131 titre\u015fim, elektrikli i\u015flemede de\u015farj \u00e7ukurlar\u0131 vb. Gibi di\u011fer fakt\u00f6rler taraf\u0131ndan olu\u015fturulur. Fark nedeniyle. i\u015fleme y\u00f6ntemine ve i\u015f par\u00e7as\u0131 malzemesine ba\u011fl\u0131 olarak, i\u015flenmi\u015f y\u00fczeyde kalan izlerin derinli\u011fi, yo\u011funlu\u011fu, \u015fekli ve dokusu farkl\u0131d\u0131r.<\/strong><\/p>

\"\"<\/figure>

Y\u00fczey P\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn Par\u00e7alar \u00dczerindeki Ana Etkisi<\/strong><\/strong><\/h2>

A\u015f\u0131nma direncini etkiler.<\/strong><\/strong><\/h3>

Y\u00fczey ne kadar p\u00fcr\u00fczl\u00fcyse, y\u00fczeyler aras\u0131ndaki etkin temas alan\u0131 o kadar k\u00fc\u00e7\u00fck, bas\u0131n\u00e7 o kadar b\u00fcy\u00fck, s\u00fcrt\u00fcnme direnci o kadar y\u00fcksek ve a\u015f\u0131nma o kadar h\u0131zl\u0131 olur.<\/strong><\/strong><\/p>

Koordinasyonun kararl\u0131l\u0131\u011f\u0131n\u0131 etkiler.<\/strong><\/strong><\/h3>

Bo\u015fluk uyumu i\u00e7in, y\u00fczey ne kadar p\u00fcr\u00fczl\u00fc olursa, a\u015f\u0131nma ve y\u0131pranma o kadar kolay olur ve \u00e7al\u0131\u015fma s\u00fcrecinde bo\u015fluk kademeli olarak artar. Giri\u015fim uyumu i\u00e7in, montaj s\u0131ras\u0131nda mikro d\u0131\u015fb\u00fckey tepelerin ekstr\u00fczyonu nedeniyle ger\u00e7ek etkili giri\u015fim azalt\u0131lacak ve ba\u011flant\u0131 g\u00fcc\u00fc azalacakt\u0131r.<\/strong><\/strong><\/p>

Yorulma mukavemeti etkilenir.<\/strong><\/strong><\/h3>

P\u00fcr\u00fczl\u00fc par\u00e7alar\u0131n y\u00fczeyinde b\u00fcy\u00fck oluklar vard\u0131r. Keskin \u00e7entikler ve \u00e7atlaklar gibi, par\u00e7alar\u0131n yorulma mukavemetini etkileyen gerilim konsantrasyonuna kar\u015f\u0131 hassast\u0131rlar.<\/strong><\/strong><\/p>

Korozyon direncini etkiler.<\/strong><\/strong><\/h3>

P\u00fcr\u00fczl\u00fc par\u00e7alar y\u00fczeyi, mikro-vadi s\u0131zmas\u0131n\u0131n y\u00fczeyinden metal i\u00e7 tabakaya n\u00fcfuz eden a\u015f\u0131nd\u0131r\u0131c\u0131 gazlar veya s\u0131v\u0131lar yapmak kolayd\u0131r, bu da y\u00fczey korozyonuna neden olur.<\/strong><\/strong><\/p>

S\u0131zd\u0131rmazl\u0131\u011f\u0131 etkileyen<\/strong><\/strong><\/h3>

P\u00fcr\u00fczl\u00fc y\u00fczeyler s\u0131k\u0131ca oturmaz ve temas y\u00fczeyleri aras\u0131ndaki \u00e7atlaklardan gazlar veya s\u0131v\u0131lar s\u0131zar.<\/strong><\/strong><\/p>

Temas sertli\u011fi etkilenir<\/strong><\/strong><\/h3>

Temas sertli\u011fi, par\u00e7alar\u0131n d\u0131\u015f kuvvet alt\u0131nda temas deformasyonuna direnme yetene\u011fidir. Makinenin sertli\u011fi b\u00fcy\u00fck \u00f6l\u00e7\u00fcde par\u00e7alar aras\u0131ndaki temas sertli\u011fine ba\u011fl\u0131d\u0131r.<\/strong><\/strong><\/p>

\u00d6l\u00e7\u00fcm do\u011frulu\u011fu etkilenir<\/strong><\/strong><\/h3>

\u00d6l\u00e7\u00fclen par\u00e7alar\u0131n ve \u00f6l\u00e7\u00fcm aletlerinin y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc, \u00f6zellikle hassas \u00f6l\u00e7\u00fcmde, \u00f6l\u00e7\u00fcm\u00fcn do\u011frulu\u011funu do\u011frudan etkileyecektir.<\/strong><\/strong><\/p>

Ayr\u0131ca y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn kaplama, \u0131s\u0131l iletkenlik ve temas direnci, yans\u0131tma ve radyasyon performans\u0131, s\u0131v\u0131 ve gaz ak\u0131\u015f\u0131n\u0131n direnci ve iletken y\u00fczeyindeki ak\u0131m ak\u0131\u015f\u0131 \u00fczerinde farkl\u0131 etkileri vard\u0131r.<\/strong><\/strong><\/p>

Y\u00fczey P\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn De\u011ferlendirme Esas\u0131<\/strong><\/strong><\/h2>

\u00d6rnekleme Uzunlu\u011fu<\/strong><\/h3>
\"\"<\/figure>

\u00d6rnekleme uzunlu\u011fu, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn ya\u015f\u0131n\u0131 de\u011ferlendirmek i\u00e7in bir referans \u00e7izgi uzunlu\u011fudur. Par\u00e7an\u0131n ger\u00e7ek y\u00fczeyinin olu\u015fum ve doku \u00f6zelliklerine g\u00f6re y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck \u00f6zelliklerini yans\u0131tan kesitin uzunlu\u011fu se\u00e7ilmeli ve \u00f6rnekleme uzunlu\u011fu ger\u00e7ek y\u00fczey profilinin toplam y\u00f6n\u00fcne g\u00f6re \u00f6l\u00e7\u00fclmelidir. \u00d6rnekleme uzunlu\u011fu, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn \u00f6l\u00e7\u00fcm sonu\u00e7lar\u0131 \u00fczerindeki y\u00fczey dalgalanmas\u0131n\u0131n ve \u015fekil hatas\u0131n\u0131n etkisini s\u0131n\u0131rlamak ve azaltmak i\u00e7in tan\u0131mlan\u0131r ve se\u00e7ilir.<\/strong><\/p>

De\u011ferlendirme uzunlu\u011fu<\/strong><\/h3>
\"\"<\/figure>

De\u011ferlendirme uzunlu\u011fu, konturu de\u011ferlendirmek i\u00e7in gerekli bir uzunluktur. Bir veya daha fazla \u00f6rnekleme uzunlu\u011fu i\u00e7erebilir. Par\u00e7a y\u00fczeyinin her bir par\u00e7as\u0131n\u0131n y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc mutlaka tek tip olmad\u0131\u011f\u0131 i\u00e7in, belirli bir y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn \u00f6zelliklerini bir numune alma uzunlu\u011funa yans\u0131tmak genellikle mant\u0131ks\u0131zd\u0131r, bu nedenle y\u00fczeyi de\u011ferlendirmek i\u00e7in y\u00fczey \u00fczerinde birka\u00e7 numune alma uzunlu\u011fu almak gerekir. p\u00fcr\u00fczl\u00fcl\u00fck. De\u011ferlendirme uzunlu\u011fu genellikle be\u015f \u00f6rnekleme uzunlu\u011funu i\u00e7erir.<\/strong><\/p>

referans hatt\u0131<\/strong><\/h3>

Referans \u00e7izgisi, y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck parametrelerini de\u011ferlendirmek i\u00e7in kullan\u0131lan kontur orta \u00e7izgisidir. \u0130ki t\u00fcr referans \u00e7izgisi vard\u0131r: konturun en k\u00fc\u00e7\u00fck kareler orta \u00e7izgisi: \u00f6rnekleme uzunlu\u011fu i\u00e7inde, kontur \u00e7izgisi \u00fczerindeki her noktan\u0131n anahat ofsetinin toplam\u0131 en k\u00fc\u00e7\u00fckt\u00fcr ve geometrik bir kontur \u015fekline sahiptir. Aritmetik ortalama kontur orta \u00e7izgisi: \u00d6rnekleme uzunlu\u011fu i\u00e7inde, orta \u00e7izginin her iki taraf\u0131ndaki kontur alan\u0131 e\u015fittir. Teoride, en k\u00fc\u00e7\u00fck kareler orta \u00e7izgisi ideal bir referans \u00e7izgisidir, ancak pratik uygulamada elde edilmesi zordur. Bu nedenle, konturun aritmetik ortalama orta \u00e7izgisi genellikle onun yerine kullan\u0131l\u0131r ve \u00f6l\u00e7\u00fcmde bunun yerine yakla\u015f\u0131k konumu olan bir \u00e7izgi kullan\u0131labilir.<\/strong><\/strong><\/p>

Y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc de\u011ferlendirme parametreleri<\/strong><\/strong><\/h2>

Y\u00fckseklik karakteristik parametreleri<\/strong><\/h3>

Ra kontur aritmetik ortalama sapmas\u0131: \u00f6rnekleme uzunlu\u011fu (lr) i\u00e7indeki kontur ofsetinin mutlak de\u011ferinin aritmetik ortalamas\u0131. Pratik \u00f6l\u00e7\u00fcmde, \u00f6l\u00e7\u00fcm noktalar\u0131n\u0131n say\u0131s\u0131 ne kadar fazlaysa Ra o kadar do\u011fru olur.<\/strong><\/strong><\/p>

Rz konturunun maksimum y\u00fcksekli\u011fi: kontur zirvesinin \u00fcst \u00e7izgisi ile vadinin alt \u00e7izgisi aras\u0131ndaki mesafe.<\/strong><\/strong><\/p>

Ra, yayg\u0131n olarak kullan\u0131lan genlik parametreleri aral\u0131\u011f\u0131nda tercih edilir. 2006'dan \u00f6nce, ulusal standarttaki di\u011fer bir de\u011ferlendirme parametresi, Rz ile ifade edilen \u201c10 noktal\u0131 mikro p\u00fcr\u00fczl\u00fcl\u00fck y\u00fcksekli\u011fi\u201d ve Ry ile ifade edilen maksimum kontur y\u00fcksekli\u011fi idi. 2006'dan sonra, ulusal standartta 10 noktal\u0131 mikro p\u00fcr\u00fczl\u00fcl\u00fck y\u00fcksekli\u011fi iptal edildi ve maksimum kontur y\u00fcksekli\u011fi Rz ile ifade edildi.<\/strong><\/strong><\/p>

Aral\u0131k karakteristik parametreleri<\/strong><\/h3>

RSM kontur biriminin ortalama geni\u015fli\u011fi. \u00d6rnekleme uzunlu\u011fu i\u00e7inde, kontur mikro p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fcn ortalama mesafesi. Mikroskobik d\u00fczensizlik aral\u0131\u011f\u0131, orta hattaki kontur tepelerinin ve biti\u015fik kontur vadilerinin uzunlu\u011funu ifade eder. Ayn\u0131 Ra de\u011feri olmas\u0131 durumunda, Rsm de\u011feri mutlaka ayn\u0131 de\u011fildir, dolay\u0131s\u0131yla yans\u0131yan doku farkl\u0131 olacakt\u0131r. Dokuya \u00f6nem veren y\u00fczey genellikle iki g\u00f6sterge olan Ra ve Rsm'ye dikkat eder.<\/strong><\/strong><\/p>

Rmr'nin \u015fekil karakteristik parametreleri, kontur deste\u011finin uzunlu\u011funun \u00f6rnekleme uzunlu\u011funa oran\u0131 olan kontur deste\u011finin uzunluk oran\u0131 ile ifade edilir. Kontur deste\u011finin uzunlu\u011fu, orta hatta paralel ve kontur tepe \u00e7izgisi C ile kesi\u015fen \u00f6rnekleme uzunlu\u011fu i\u00e7indeki her b\u00f6l\u00fcm\u00fcn kesit uzunluklar\u0131n\u0131n toplam\u0131d\u0131r.<\/strong><\/strong><\/p>

Y\u00fczey P\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc \u00d6l\u00e7\u00fcm Y\u00f6ntemi <\/strong><\/h2>

kar\u015f\u0131la\u015ft\u0131rma y\u00f6ntemi<\/strong><\/h3>

At\u00f6lyenin saha \u00f6l\u00e7\u00fcm\u00fcnde kullan\u0131l\u0131r ve genellikle orta veya p\u00fcr\u00fczl\u00fc y\u00fczey \u00f6l\u00e7\u00fcm\u00fcnde kullan\u0131l\u0131r. Y\u00f6ntem, \u00f6l\u00e7\u00fclen y\u00fczeyin belirli say\u0131da p\u00fcr\u00fczl\u00fcl\u00fck numunesi ile kar\u015f\u0131la\u015ft\u0131r\u0131larak \u00f6l\u00e7\u00fclen y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck de\u011ferinin belirlenmesidir.<\/strong><\/strong><\/p>

dokunmatik i\u011fne y\u00f6ntemi<\/strong><\/h3>

Y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc, e\u011frilik yar\u0131\u00e7ap\u0131 yakla\u015f\u0131k 2 mikron olan bir elmas kalemle \u00f6l\u00e7\u00fclen y\u00fczey boyunca yava\u015f\u00e7a kaymaktad\u0131r. Elmas kalemin yer de\u011fi\u015ftirmesi, bir elektrik uzunluk sens\u00f6r\u00fcnden bir elektrik sinyaline d\u00f6n\u00fc\u015ft\u00fcr\u00fcl\u00fcr. Amplifikasyon, filtreleme ve hesaplamadan sonra y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck de\u011feri bir g\u00f6sterge aleti ile g\u00f6sterilir. \u00d6l\u00e7\u00fclen b\u00f6l\u00fcm\u00fcn profil e\u011frisi de bir kay\u0131t cihaz\u0131 ile kaydedilebilir.<\/strong><\/strong><\/p>

Genel olarak, sadece y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck de\u011ferini g\u00f6sterebilen \u00f6l\u00e7\u00fcm aletine y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fc \u00f6l\u00e7\u00fcm aleti, y\u00fczey profili e\u011frisini kaydedebilen y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck profilleyiciye ise y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fck profilleyici denir. Bu iki \u00f6l\u00e7\u00fc aletinde elektronik hesap devresi veya bilgisayar bulunur. Konturun aritmetik ortalama sapmas\u0131n\u0131 Ra, mikro p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn 10 noktal\u0131 Rz y\u00fcksekli\u011fini, konturun maksimum Ry y\u00fcksekli\u011fini ve di\u011fer de\u011ferlendirme parametrelerini otomatik olarak hesaplayabilirler. Y\u00fcksek \u00f6l\u00e7\u00fcm verimlili\u011fine sahiptirler ve 0,025 ile 6,3 um aras\u0131nda de\u011fi\u015fen Ra y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcn\u00fc \u00f6l\u00e7mek i\u00e7in uygundurlar.<\/strong><\/p><\/div>","protected":false},"excerpt":{"rendered":"

We are aware of that surface roughness means a lot in manufacturing industry. When the concept is recalled to your mind, there must be some common textures on machined parts, such as bright mirror surface, matte, and dull polish. They are what different surface roughness embodies in macroscopic condition. Definition of surface roughness As is…<\/p>","protected":false},"author":2,"featured_media":19301,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-3800","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cutting-tools-weekly"],"jetpack_featured_media_url":"https:\/\/www.meetyoucarbide.com\/wp-content\/uploads\/2019\/10\/\u56fe\u72471-3.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/3800","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/comments?post=3800"}],"version-history":[{"count":0,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/3800\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media\/19301"}],"wp:attachment":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media?parent=3800"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/categories?post=3800"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/tags?post=3800"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}